I've been just boiling them for Euro mounts in recent years, but as a kid I helped my Grandpa mount bucks with a process similar to what you did. We would screw the horns on a larger plaque, plaster a round section, then cover with vinyl and tack the edges.
I've also done them similar to the way you have on a small board, but taped the bases and used expanding foam. After the foam cures, you can carv it to the desired shape, wrap vinyl or cotton cloth around(stapling to the rear of the board), then screw through the rear of a larger plaque into the smaller bd. Makes for a clean mount either way, the foam method is just much easier.
Good job.
loder
