Very nice looking work! I hope you will post a picture or two (or a link to same) taken with the new back.
On my long term list of projects is making an adapter back to use a torpedo camera roll film holder on one of my view cameras. I've considered a slider back so the ground glass wouldn't have to be removed, but that would make it heavier and bulkier I suppose.
It would be nice to make a custom rear standard to use the torpedo roll holder on my 4X5 Sinar Norma, but that would involve making a bellows. Learning bellows making is also on my project list. However getting a Cirkut camera running comes ahead of all those ideas.
Len