The FH, along with other swinging arm Ariels of the period has an unusual feature used to mount the tail light vertically - a little pressed steel plinth, part number 5611-55. Drags do a very nice replica for about £15, but they have been out of stock for a while and it is an easy thing to make.
Starting with the Lucas 564 rear lamp, we need a caliper, some plastic holes, a piece of card and a scalpel.
I used the holes and the caliper to mark out three holes in the card - one for the bulb holder and two for the mounting bolts. Then I can fit the lamp to the card and draw around it:
Next, I can develop the part around the shape of the lamp:
Cut it out with the scalpel, using a wad punch for the holes if you have one of a suitable size. In my case, I punched the smaller holes and used a swivelling scalpel for the larger one:
Next, make some nice sharp folds with a ruler and use staples or a glue gun to fix the edges which will eventually be welded:
With the part to the shape we want, we can undo the staples and stick the pattern to a suitable steel sheet. It's that old bread bin again, that gave us the air filter for the QR50:
I used the bandsaw to cut it out, but you can use a hacksaw, shears or whatever you have. The edges are cleaned and deburred with a variety of files.
Folding is quite straightforward using just the vice and my trusty bit of copper bar. With folding completed, the next step is to weld up the joints - most of which came together to weld autogenously. The linisher springs into action to clean it up:
After a couple of trial fits and a bit more time on the linisher, I treated the plinth to a bit of UPol etch primer before fitting it to the bike - temporarily, with a few magnets:
I think it looks fine.
