They had to be Rossi model 62's. They were made in many variations. Copies of the Winchester model 62 rifle. Blued, Nickled, Stainless and different stocks and barrel lengths. They should be fairly easy to find at gun shows. They were popular sellers when they first came out.
That was my thought, as well. I can't think of anyone else that had a nickel plated pump action rimfire during that same time period. ...And the Rossi pumps had more "kid appeal" than other brands, for some reason.
I had one of the laminate stock, nickel plated "Gallery" models... for about a day. It suffered from the same issues that plagued the entire line of Rossi 62s: feeding and ejection issues.
This little blue "Gallery" was purchased new, by my father, and later passed on to me. It has never suffered from any of the "standard" issues seen in the Rossi 62s. I believe the proper model designation for this is: 62SAC Gallery.
(The stock isn't beat up - as the photo makes it appear. Those marks are odd reflections from the accent lighting in the room.)
If I had to wager a guess, I'd put its round count over 100k rounds fired. It's running 100% original parts, but was of very early production.
I'm also a half-owner in a Rossi 62SA (longer, rifle version). It is of later production (1988-ish), and had issues from day one. My grandfather tried to "fix" it, but ended up butchering the cartridge elevator, hammer, and trigger. Two local gunsmiths declared the rifle "unsalvageable" while my father owned it, due to the cost of replacement parts (not because it was unsafe).
It was given to me as a "parts rifle". However, it had already been claimed by one of my other brothers... We decided a split-ownership arrangement was best.
So, I spent some time reworking the parts that I had (Winchester 62A extractor, Rossi Hammer and Cartridge Elevator), and the other half-owner tracked down a Winchester 62A trigger.
It runs flawlessly, now.
As for the gun show availability... I have NEVER seen a used Rossi 62. I know they're out there, and many are considered "junk guns" by their owners. But I've never seen one. I wish I could find a few. I really like these unloved Rossi pumps. Knowing the action intimately means it's very easy for me to salvage the "dead", as well.
And, I hate to admit it... but replacement parts are a nightmare. I need at least one "junk" 62 to keep the others alive. They're not bad rifles that fail often, but they're getting a little 'long in the tooth'. They have to fail eventually...
I think there have been a total of 5 Rossi 62s in my family. Only the blued 62SAC Gallery has been 100% reliable. The other 4 had major issues, and only 3 remain (the Gallery, 62SA, and another 62SA that is my uncle's "wall hanger").