Manhattan Arms Co. 10g Hammer

[Andy]

Saw this today at a sporting good store close to me. I know nothing about them, hammer 10g. Amazingly it points pretty well and doesn't seem as heavy as I'd expect. Seems in fair to good shape, bores look pretty good. Not sure it's worth another look from me, it's way south of a grand. This and a half dozen others out of an estate sale, the rest were severely pitted inside for the same money (Ithacas and some name I didn't recognize on another). One gun had double hammers but damn if he or I could figure out how to open it, there were no levers or signs of a lever or lifter present anywhere! Then he said, sure hope it ain't loaded. Anyways it's 30 minutes away, any thoughts on these? I read a little on line.