No need for that.
Take 2 pieces of two-by four, about 20 inches long each( cut off square at the ends), and run the center of each through a tablesaw. Stop the cut while you are still a few inches from the end. To know how far from the end to stop, figure the distance/difference between the back of your elevators and the back of your rudder, leaving minimally the same - preferably a little longer - as the distance between where the cut ends and the end of the wood. Do this a few times, increasing the width of the cut each time until the slot will hold your elevator and horizontal stab. If you rudder is shorter (not likely), then any distance you decide on will work.
Take your two pieces, slide them over your elevator/stabs, and you can stand the plane on the ground, even though you already assembled your tail feathers.
Then stand the fuse against the work bench (with some padding), and run a number of tapes around it and tape it to the workbench, with the open part facing you so you can best access the back of the firewall as you work. Secure it so the firewall is approximately level.
If your landing gear is already mounted, take two long, thin pieces of wood and drill a hole though each near the end, and run a screw (or the axle) through the gear and the wood. Then, clamp the two pieces of wood to the side of the workbench as they hang straight down. Secure it so the firewall is approximately level.
I hope this helps.
~ Jim ~