Today I finally finished a mount for the firewall, and was able to get the fuselage onto the rotisserie.
The mount is made of angle iron and 2×4, and is bolted onto the firewall in 4 corners where the engine mount will go. I had to ream the holes (per plans), and used a combination of AN-6 bolts, rubber washers, and nuts to secure the mount to the firewall.
With the mount on, I assumed I would need a couple of helpers to get the fuselage down from the work benches to the rotisserie, but was able to get it done by myself. I hoisted the fuse up using rope suspended from rafters, moved the tables out of the way, then eased it down onto a couple of low saw horses. By lifting the tail I was able to line up the mount with the rotisserie, and it slid into place no problem. Then I was able to remove the saw horses, lower the tail onto a saw horse, and it was done.