Sony didn't make projection TVs capable of 1080p for very long, if at all. Projection TVs of that age will almost certainly have a dying and faded bulb in them. I've never seen HDMI on a Sony TV to be honest, only component capable of 1080i. They expect it to be SD or "enhanced definition". Also, they're very heavy and difficult to move. That's probably why you're not getting bites.
Might want to put "trade for welding" in the title. You'll get a lot more eyeballs here.