R80/7 throttle cable options

So, busy with my custom build and whilst trying to fit the clutch perch assembly onto the handlebars, I completely fucked it up. Throw away.

So I figured, I had an aftermarket switch assembly that I prefer anyway and an aftermarket throttle assembly. Why not use these instead.

Question is, how do I get the throttle assembly, single cable to actuate both carb cables. My R65 had a cable splitter inline but the bit on the throttle end will be different to this generic unit that I have.

Any ideas?