OK... so I just tidied up the desk and found the flasher module kit lying under a bunch of old stuff and thought I would go install it... Took the light off the car brought into the living room spliced everything together and then thought about the module banging about in there. Didn't have any foam like Michael used (see 1st post) but carved a rectangular pencil eraser into a u-shape to hold the module. (My wife just lost a souvenir eraser from the National Gallery in London out of her pencil box
Anyway bolted back on the car - it works! My first mod completed after 27,000 miles and the part sitting on my desk since a couple of weeks after Michael posted. I just ordered Multi-vex mirrors today... I hope my lead time improves on the next project!