Back in the early 1980's I worked part-time at a gun shop that sold scores of the S&W 1000's. IIRC, what everyone liked about them was the stainless steel tube mag and the gas piston operation. I believe the piston would allow powder residue to accumulate inside the forend, which was easy to stay on top of and a feature that many seemed to like. Its been years since I've disassembled one, but I believe the gas piston was in the end of the mag tube and would pop up. I vaguely recall one of the sales pitches was that the piston operation was self cleaning. The shotguns were very attractive and light weight due to the alloy receiver. They came with very nice scrolling on the receiver and a Remington style finish on the wood. The wood itself seemed to be very nice walnut. I also recall that the bluing on the barrel was very nice. Of course, its hard to say definitely, but if there were any returned, it was so few that it did not make an impression.
I have kicked my self many times for not purchasing one, given that I would have been able to do so at the dealer price. At that time I would not purchase firearms that had "Made in Japan" stamped on the side. Because of that, I also do not have any Japan A-5's and many other firearms that are now considered quality products. Live and learn, huh?
I think that sometime in the mid-80's S&W stopped offering the Mod 1000 and a bolt action rifle marketed as a Mod 1500. Afterward, for a short while, Mossberg began marketing the same models under their moniker.
I don't see used Mod 1000's very often in my area, but when I do they are usually near $400 for very good examples. I recall seeing one not long ago with rough bluing and a cracked forend for $250.
I don't know about parts availability, but it seems as though you have a fine shotgun.
Enjoy.
Hope this helps.
