"Do I try to re-stone the engagement surfaces myself?"

NO, not unless you've got the stoning jigs and the knowledge to use them correctly.

In any case, if you buy a matched "drop-in" set you shouldn't need to do any stoning on a service grade gun.
Unless this is a target pistol or a range toy, a super nice, light trigger isn't necessarily desirable, as you've just found out.
They often give trouble.

I suggest you also buy a new sear spring, and DON'T start bending around on it trying for a lighter trigger.

The best "fix" is to find a good pistolsmith who knows what he's doing and let him repair it the RIGHT way.

Decide whether this is a "business" gun or a range toy.  If it's a range toy, by all means try for the finest trigger you can get, but be prepared for problems like this.

If it's a business gun, get a decent service gun "drop-in" assembly and don't alter it.  These will last for many years with no problems.

You can get a kit from Nowlin or EGW for around $80 that will drop in.

You can use the elongated loop hammer in place of the spur hammer.  It's the spur hammer that won't work with the beavertail, not the other way around.  

Chip McCormick also offers a decent hammer & sear for about half that price.  It won't be stoned for the best pull, but it will work out of the box.

I would also get a new sear spring.  They are cheap, and you start out with a known good part.  Avoid the super-cheap ones like Masen, etc.  

I had a Colt that had the same problem.  The hammer would follow the slide.  After a little trouble shooting I concluded that the problem was caused by the inertia of the slide.  When the slide slammed home, the gun jerked forward.  The trigger was light enough that the forward motion of the gun was enough to trip the sear.  Think trigger = ketchup/gun = bottle.  If you hit an inverted ketchup bottle upwards, the ketchup inside comes shooting out.  This is exactly what was happening with my trigger.

I was able to verify this by allowing the slide to slam home while keeping my hand off of the grip safety.

Quoted: by sear spring you mean the leaf / finger spring that goes under the mainspring housing? Thanks!

Correct.

Definite +1 on 'dfariswheel'. He knows what he is talking about. Charles the Gunsmith.  

Before you go spending too much money on drop in anything purchase a new sear spring or what you're calling the leaf spring.

Purchase some replacement pins for the hammer and sear.

1911 parts should be fitted, but sometimes you get lucky with drop in parts.

If your not too far away from Michigan I'll look it over for you.  Your holes in the frame may be out of spec.  or the alignment of the sear to hammer is off.

My e-mail is in my profile if you want to take me up on looking it over.

Quoted: I had a Colt that had the same problem.  The hammer would follow the slide.  After a little trouble shooting I concluded that the problem was caused by the inertia of the slide.  When the slide slammed home, the gun jerked forward.  The trigger was light enough that the forward motion of the gun was enough to trip the sear.  Think trigger = ketchup/gun = bottle.  If you hit an inverted ketchup bottle upwards, the ketchup inside comes shooting out.  This is exactly what was happening with my trigger. I was able to verify this by allowing the slide to slam home while keeping my hand off of the grip safety.

How do you fix this problem?

Quoted: Quoted: I had a Colt that had the same problem.  The hammer would follow the slide.  After a little trouble shooting I concluded that the problem was caused by the inertia of the slide.  When the slide slammed home, the gun jerked forward.  The trigger was light enough that the forward motion of the gun was enough to trip the sear.  Think trigger = ketchup/gun = bottle.  If you hit an inverted ketchup bottle upwards, the ketchup inside comes shooting out.  This is exactly what was happening with my trigger. I was able to verify this by allowing the slide to slam home while keeping my hand off of the grip safety. How do you fix this problem?

Adjust the left leaf of the sear spring to apply more pressure to the sear.  Also replace the trigger with a lighter one if necessary.

Thank you Sir.

Quoted: Quoted: Quoted: I had a Colt that had the same problem.  The hammer would follow the slide.  After a little trouble shooting I concluded that the problem was caused by the inertia of the slide.  When the slide slammed home, the gun jerked forward.  The trigger was light enough that the forward motion of the gun was enough to trip the sear.  Think trigger = ketchup/gun = bottle.  If you hit an inverted ketchup bottle upwards, the ketchup inside comes shooting out.  This is exactly what was happening with my trigger. I was able to verify this by allowing the slide to slam home while keeping my hand off of the grip safety. How do you fix this problem? Adjust the left leaf of the sear spring to apply more pressure to the sear.  Also replace the trigger with a lighter one if necessary.

Just to clarify a couple of things and avoid confusion:
IN RED:  I was referring to the lightness of the trigger pull, not the trigger's mass
IN BLUE (posted by ken mays):He was referring to the actual weight of the trigger, not the trigger pull weight.

I just put this set into a Springfield "Officer" model and it worked perfectly.  Parts are very high quality with no fitting required.  I also replaced the leaf spring with a Wolff part.

Gentlemen,

Don't belive the hype of needing to replace hammers and sears because of hammer follow, unless you had a trigger job done or you have had a lot of hammer follows.  Like you just kept cycling the pistol as if it would fix itself.  
For stock parts look at your sear and hammer after you pull them out of the pistol, if the two mating surfaces have cracks, chips or are rounded out then get new parts.

Just a bit of hinting of what each leaf on the sear spring does.
Holding the sear spring as it is set in the pistol:
Left leaf (the one with the hook) is to hold the sear against the hammer.
Center leaf is to push the trigger forward.
Right leaf is to push back the grip safety.

So If you bend the left leaf forward it will cause the sear to engage the hammer with more force and also makes your trigger pull heavier.

If you bend the center spring forward it will make your trigger heavier and help to reduce the trigger bounce problem.

Pull the right leaf back and you grip safety will need a firmer grip.

Most people don't understand that all most 1911's need is adjustment of the sear spring.
But you need to have a quality sear spring so that it retains the adjustment.  Many of the pistols these days come with substandard sear springs that don't hold adjustments well.  

DO NOT MESS WITH THE SEAR SPRING TO LIGHTEN YOUR TRIGGER PULL UNLESS YOU KNOW WHAT YOU ARE DOING.  IT CAN CAUSE ACCIDENTAL DISCHARGE IN A WORST CASE SITUATION!!!!  Leave trigger jobs to the gunsmiths.

When you're talking about overstoned or rounded off hammers and sears, it can be tough for the uninitiated to know what to look for.  One thing you can do is to start off with a known good set of parts that hasn't been screwed up.

It may not be necessary to replace the ignition parts, a new sear spring may be all he needs.