Motorcycle Pannier Mounts

I bought some panniers from eBay and they came with nothing to mount them to my motorcycle.
I set off prototyping some mounts and thought I would add them here in case they help.
It should clamp to a 12mm pannier bar

I am going to print these in ABS but I have prototyped in PLA and they seem to fit fine.
They should clamp a pannier bar securely but maybe a small piece of bike inner tube would create a seal for a tighter grip.

I used double sided tape to pre-mount them for lining up so