What are you planning to do about the gaskets for the 3/4" fittings? BobbyM was right - these things are much bigger than the 1/2" size.
I have a 3/4" camlock that I bought some #317 silicone o-rings from o-rings and more. The OD of the oring is a bit on the small side. It still seems to be retained by the internal groove - I can't shake it out, but I have not brew tested it yet.
Curious if you had another idea.