Found a 1st year production Remington 870 12ga today.

I found a 1st year manufacture Remington 870 12ga today, 4 digit sn, 26" full choke barrel w/matching sn,
barrel has a Cutts type compensator on it, not marked Wingmaster, small forend and the buttstock may be
a replacement because it does not match forend and buttplate is smaller than the stock end.
Metal is about 90% overall, I was going to cut the barrel and install some Wilson Scattergun Technology
sights ect,ect but sure would hate to mess up a collector , what say you ?
Any Remington GURU's out there ?

It probably doesn't have any collector's value but it is enough of a conversation piece that I wouldn't modify it. 870s are inexpensive enough to buy another one to mod or at least another barrel.

Good find.
In agreement with GH41; get an aftermarket barrel.

Send it to Wilson for their 870 Steal Package. They will cut the barrel and do any modifications you want in terms of sights etc...they will add new synthetic stocks but most importantly they will convert it to a 3" chamber and add the Flex Tab conversion to your trigger group. Best deal going.

It will go to Wilson !