Thanks for everyone's help.
I ended up with a compromise that I think gives the best of all aspects - access, aesthetics, limited mods to original etc
I made an angled bracket out of 15/10 sheet that just grips the front edge of the JT5 casting with a slight fold and is held in place with a 1/4 UNC bolt tapped into the JT5.
The Cunifer hose comes up at an angle to the back of the bracket and picks up the original type/length rubber hose,
which itself goes back to Cunifer on the original L-shaped bracket - but which I moved from one front-frame anchorage bolt to another.
All of it clears inlet-manifold and float-bowl stuff and choke cable. The rear carb throttle-return spring post is very close to the Powerlite and might need tweaking on some cars.
Hope this helps someone.