Here are a couple of vintage Gravely's on auction at a local school district. At least 1 is an LI model. They both appear to have the old round fuel tanks.
If anyone's interested, PM me and I can go look at them tomorrow. I can also arrange to pick them up and hold them for a limited time--2-3 weeks, while you arrange transportation.
The appear to have the original Gravely T-head engines in them, plus lots of good spare parts, or maybe they could be put together and you'd get a running engine.
Sorry, but I can't download a copy of the pictures...