NEED Answers, I just don't know

Hello everyone, I'm here with another question and quite frankly I have NO idea what the answer is or should be.

 I have a Gun Show coming up this weekend (Oct 15th and 16th) in Virginia Beach.  The vendor that sold me my first IBM Carbine (Blondie) will be there.  He is bringing another IBM for me to look at along with a few parts (AOB Flat Bolt, BOB Sear, and a couple of firing pins).  He and I have struck a friendship and I trust him as to what he has to offer (as much as you can trust any vendor at a gun show).  I realize he is in to make as much profit as possible, that is his business.  My job is to buy it for as little money as he will take.

 However, he is from Florida and got hit with the past storm and is trying to put dollars back together.  during his "Clean Up" he found a wooden crate he had stored in his warehouse that is supposedly "Unmolested" and is bringing it up for my examination and possible purchase.  My problem is I have NO Idea how much it is worth or what I should Offer/Pay/Buy it for.

 The wooden crate is filled with 100, IBM Factory Magazines, still in the wrapper.  It was not exposed to any water damage in the storm.  It is supposed to have the factory certification/inventory sheet still inside.  I know it is worth a bunch and I know the going rate of new single original factory Mags can be worth $100 or more.  How much would an “Unmolested” NOS IBM Mags be worth?

 How much is it worth? What should I offer?  What would be max is should pay?

 Very respectfully,

 Da1Chief

Like my first one it is an IBM (Not and AO) Serial Number 3762334 on "I.B.M. CORP." Receiver.

Did a basic "Field Strip" this morning:  From what I see it has a lot of the correct parts in/on it.

"I.B.M. CORP" Barrel dated what appears to be 9   -43 (which should put MFG date somewhere in the Nov 43 timeframe)

Flaming Bomb located below barrel date, there is a small (approx. 1/8" tall) "P" on the barrel 1/2 down barrel from muzzle. to the Gas Piston, "P" is slightly angled from top of "P" to bottom, Left Side to Right Side (Not sure what it means, from what I have read the factory stamp "P" should be larger)

Front Sights appear to be type 1 and are stamped “N”, Rear Sights appear to be type 2 and have “H” (Inside of Shield)

"AOB" Flat Bolt (have not disassembled to check parts at this time), WMB Hammer, BOB Sear (again, have not disassembled to check it further)

Stock is stamped "SCB" in Sling Well, Hand Guard is "2 Rivet" stamped "SCB" on left side a little less than 1/2 way up from rear to muzzle.  Both Stock and Hand Guard are so dirty, I can't tell if it is Stained Birch or Black-Walnut. It is so dirty that my hands stick to it when I pick it up.

All the components do not look as though they have been cleaned in quite a while.

So here is the Question:  Other than a basic cleaning barrel bore, trigger assembly, and receiver (Using “Hoppes #9), Should I clean the stock with Formby Refinisher, Mineral Spirits or something milder? (I just hate to lose the Petina like I did on my first carbine).   Recommendations are Greatly Appreciated!  I’m at a loss as what to use.