Chinakay,
Thanks a lot! I had a feeling it might be tricky to date. The clothes just look so ... generic, somehow. And, yeah, there's not a lot else -- no frame, studio name, nothing on the back. I think the style of backdrop looks really similar to this photo from the same side of the family, but it isn't dated, either, so. At least I know who it is -- my gg grandfather, which might indicate the tintype was also from Ohio or Indiana, since that's the area my gg grandfather lived in at the time that tintypes were a thing.