The first thing you'll need is a 6x9 graflok back. I have both versions,New and Old. They get their own corresponding groundglass. I have 6x8 and 6x9 holders.
Actually, I don't need all that and would be willing to part with the older style graflock, groundglass and the 6x8 holder. If you want to focus the Rm3d via the index marks, then you'd want to order a new "N" style graflok adapter from Rod Klukas.
I really dig shooting roll film on the little view camera and used this setup on my Rm3d too.
Let me know if you're interested in that stuff. I don't need to get much money for it.
Cheers,
CB