BlackJack, A subscription to the U. S. Martial Arms Collector magazine is $35 per year. The basic sales letter is $65. The letter will tell you to whom it was sold and the city and state where they lived. You will also get a photocopy of the sales record card. I have gotten the sales letters on all my NRA Sporters. I think it is well worth the $100.
If the stock has been shortened very much on your rifle the original type buttplate will not fit. The original length of pull to the back of the wood is 13 3/8". The buttplate can be ground away a very slight amount if that is all that is all that is needed to make it fit. Much grinding on the top or bottom of the buttplate will get into the hollow. That can be built up with weld and reshaped. You will probably have to spend $75 or $80 for a correct original steel buttplate. I have seen some aluminum buttplates but I think they were aftermarket copies.