One man's trash is another man's treasure.
This summer, I sold an 80% condition .22LR #4 solid-frame Remington RB for $375, and a home-made-cased 85% .32 Colt Short Rimfire that had a centerfire conversion for $495 - both to FFL dealers.
Mesa - That .22 roller sounds like a Remington #4, which was a "boy's rifle" sold from the 1890's through the 1920's.
There were a few changes, mostly from octagon to round barrel and from a solid frame to a weaker take-down frame with a takedown lever on the receiver ring side.
The octagon barreled one you saw sounds like an earlier, pre-1911 make.
The serial number on them is on the barrel underside, just ahead of the forend tip - along with a bore size (.22/.32/etc) designation.