Congrats, I too own an IBM (... Mainly, it has a Rock-O-La trigger group). Fortunately Academy has Monarch .30 carbine ammo, so it isn't just a safe queen.

Its a shooter.  Early bolt, late model rear sight but hey, I like these little guns and ammo is no bigger deal than ammo for anything else IMHO.

If you can, cancel the Wolff spring set and find some GI ones.  Many of the guys on the CMP forum say those Wolff springs, at least for this rifle, cause problems.

If barrel measures good you paid  top dollar. If muzzle is wore or rifle Import marked you overpaid.
Doesnt really matter now its yours, enjoy her

Don't ever rely on that slide stop button.  You will regret it.  Especially if you're finger is in front of the chamber when you release it.

I love that stock.  

Nice carbine.  

I wouldn't use a wolff spring either.  

Orion 7 springs do you right.

The one Wolfe spring I used was a Wolfe hammer spring.  It was too long by about 1/4".  So strong that there were numerous failures to eject.  USGI spinrg is about 2 1/2" long.  If the Wolf spring is much longer than that, it can cause problems.

The service manual I have states:  OD .256 +/- 0.004, ID 0.179 min, number of coils - 121, free length 10.28, solid length 4.625.  But that is for GI spring dimensions.  An aftermarket spring may be different in some respects as they may have used different steel with different properties, or they may have tried to alter the operating parameters of the rifle.  Especially if they are referred to as high or low power sets.

Yeah, from what I understand, the closer you are to 10-1/4" the better off you are.  

Having said that, a wolff spring might be the right length, but it still might be too stiff.  IDK.  I just know from people on here that some wolff springs have been known to be too stiff.  I don't know if I've ever experienced it myself.  But with these older carbines, your best bet is to stick with USGI or something comparable.  Orion7 has a good rep with the milsurp guys.  From what I can tell.  

Oh, one more thing, I bought my springs from fulton when I first got my carbine and they were too short.  I didn't realize at the time and just figured they were gtg.  But I've since learned they might do this regularly.  And my carbines haven't run properly yet.  I have to get them out since I replaced the springs.

Welcome to the club.. Neat weapons.. Reload for it.