Sometimes you can find the small CU solid copper rivets at hardware/tack stores. 1/8"
There are the type that looks like a small tack and are pointed on the end and then there are a two part type with washer.
Some are even one piece with grooves cut into them that allow them to be set/ crushed easier.
Crushing them with a c-clamp is probably better than trying to dolly them together and holding the HG at the same time.
The parts-tools are easier to manage especially on something that's brittle or old