More progress. Have the Dunstall fully mocked and fabricated the mounts/bolts. Set the tank from the 78 F I just picked up, swapped out the gas lid flaps so the key worked and set the tank. I had to re-adjust the clubmans since I had them set for the original 75 tank and they are a little different. Unfortunately that also entailed removing and re-routing the front brake line and having to re-bleed the brake. All that's left now is some slight cutting on front of the seat pan, running a new fuel line from petcock to carbs, and it's done.
Some pics.