I have successfully repaired a number of stocks.  An old-timer gun-club friend had some old Springfield stocks to sell.  Some of them were in more than 5 pieces, and some had wrist fractures.  FWIW, I had to make a point of telling the buyers of the best of them that the stocks were repaired, and pointing out the repairs.  I once repaired the stock of a family heirloom rifle of a female friend of mine that had been swung, by a former BF, against a steel basement pillar, and fractured very badly.  Some pieces were missing altogethe, as you might imagine.

I started from zero, and got to be fairly good.  You can do the same if you want/need.

My suggestion is that if you can find a good replacement stock, then go for it.  Your stock, on account of the damage, and other work done on it, sounds a bit challenging, especially to someone not familiar to doing such repairs.  

If that's not an option, then read on.

If the break is a clean one, then the stock can be glued together.   As mentioned, de-grease everything around the joint with acetone.

I would definitely remove the metal used in prior "repairs", and go from there.  You will certainly have to fill some voids, so get some sawdust of the same type of wood ready to mix with epoxy as a paste to fill the voids.  In a pinch, you an get a little wood from underneath the buttplate, but finding a same-wood donor is much better.  I would NOT use 5-minute epoxy, as this is way too quick.  Things can go wrong during the critical clamping process, and being limited to 5 minutes is way too short a time to recover.  

An absolutely critical point is to set up all the clamps and so forth beforehand and have an idea on where to set them BEFORE applying the glue, as you don't want to be fumbling around while the glue sets up.  On wood fractures that might tend to slip once glue is applied, brand-new surgical rubber tubing, (available at most pharmacies) stretched TIGHT around the fracture, will often due in lieu of clamps.

If there are any significant voids, mix some sawdust with some epoxy and fill the voids.  This mixture will certainly be darker than the original wood, so be prepared to remove the old finish and re-stain the bare wood a darker, probably much darker, color to match the patches.

I would avoid Elmer's and similar glue, as IIRC, they are not water-resistant.  Using epoxy, and getting a good result guarantees that the stock will NOT ever break at the glued joint, ever.  It may break somewhere else, maybe right next, on account of the design of the stock, but a new break will NOT be on account of an improper glue.

If you take your time setting things up, and if you have just a little luck, the break will be almost impossible to detect if you follow my advice.

Every gun store has some junk stocks around, and you can get one for maybe free to practice on.

Break one like the one you have and practice on that before you repair the family heirloom.

It is not brain surgery, but a little practice will help you a GREAT deal in getting a good job when it counts.  

As an aside, a good many stocks like yours fracture at the wrist.  The proper prevention is very long receiver tangs, top and bottom,so as to reinforce the thin wrist.

If the tangs on your receiver are not long, then you will have to do some reinforcing on your own.

You will need to get some small-diameter threaded brass or stainless steel rod from a vendor, possibly a model/RC airplane shop.  Drill holes  almost completely through the stock from the bottom, sized so that the threaded rod can be screwed into the stock wrist from underneath, after installing double nuts.  Once the rod bottoms out (by measurement), then cut flush and drill the exposed end of the rod so as to fill the drilled hole with epoxy/wood paste.  Some of the reinforcements can be done within the existing tang inletting, so that is simplified.  I would drill the holes for the rod no less than 1 " apart, and angling them a little bit off center is a good idea.  Reinforcements of this nature, I.E. wrists of stocks, run at right angles to the grain of the wood, which in this case, is from top to bottom of the wrist.

LMK if I can be of help.

OK, thanks for the update.  At this point, I suggest buying a similar fore-end so that the two pieces of wood will match.  Trying to match old wood with new in terms of color/stain/finish/wear/dings is not too easy, and something of an art.  There is not much room for second-tries.

If you go this route, I suggest using Tung oil as a finish. It will mimic the OEM finish, and is vastly superior to linseed oil, wnich was probably the OEM finish.

Tung oil will penetrate and polymerize within the wood creating an impenetrable barrier to moisture, unlike linseed oil, which requires constant re-application to achieve anything like the same effect.

If this is too much, than spray spar polyurethane, which is highly resistant to UV light and water is the way to go.  In either case, select a satin finish which always looks good, doesn't spook game on account of reflections, and hides the dings and imperfections in the wood/finish a bit better than gloss.

Whatever finish you select, coat every single inch of the wood, inside and out, fine sanding and then steel-wooling for the final coat or two.

Please do consider reinforcing the obvious weak portions of the stock with threaded brass rod, as outlined above.  If you need assistance, IM me.

If the factory had done so, you might not have had to go to all this hassle.  If this might be a family heirloom, why not go the extra step now?

Your heirs are very unlikely to be able to get a replacement stock as you did.  Just something to think about....