I'd check it out. If its under $100 and its in good condition, buy it.

Cheap and easy way to see the inside of the bore is to drop a 40-44cal brass case down the bore and use a small Mag-Lite flashlight to see down in there.

Check and make sure the double set triggers function.

If it passes inspection and the price is right, You got one hell of a Powerbelt shooter in your hands!