It is in the nature of low-volume makers like TVR that they tend to use off-the-shelf items from mainstream manufacturers' deleted models. In the case of the TVR Wedges prior to the 400SE, the front indicator/ sidelights were initially sourced fom Lucas, then later from Renault.
Even by the time TVR started using bits off it , the R12 was seriously old-hat. Renault had passed on the tooling to Romanian company Dacia, who produced the R12 as the 'Denem' up to 1984 and for a few years afterwards it had been possible to get replacement lights at a reasonable price. Nowadays it means a trip to Renault themselves, several weeks waiting and about £40 each unit (NOTE: see addendum at foot of page!). I know; I had to do that with the Tasmin after the replacement front bumper I got turned out to be the later ribbed type that needed the smaller indicators. On the 390SE these light units look like this (dead bugs were a factory option!):
The light units on my car weren't in the best of health when the offside one was smashed by a flying stone. Unwilling to pay Renault again, not wanting to wait for a new lens (at almost £20) and reasoning that even new units would corrode eventually, I decided to fabricate my own.
I laid-up a few layers of mat and resin in the recess of the front bumper. Lampholders were obtained for a couple of pounds from Vehicle Wiring Products and the new 'base' drilled to accept them. Further resin bonded the lampholders and some 3mm nuts in, a partition was added from an offcut of plastic... which left the lens. I played with a couple of ideas before settling on the solution you see: a lens cut from the diffuser of an industrial light fitting ( I guess a domestic fluorescent would do as well!), an 'inner' diffuser in white plastic which I later opted to leave out for increased brightness, and to get the requisite amber colour I used those bulbs with orange coating that modern cars have. Ironically, they were the most expensive part of the job.The new bases were screwed into the bumper, stainless domed-head hex screws and a bead of silicon sealant used to fix the lenses and keep the rain out respectively. In true TVR fashion, I had to cut two different shaped lenses as the bumper recesses are slightly different!
Home-made front indicator parts! Isn't GRP wonderful... ;)
...and the finished item prior to drilling for screws (ignore the spoiler damage!)
ADDENDUM: Whilst browsing on Ebay recently, I accidentally (honest!) found myself looking at some side/ indicator units for, of all things, the Reliant Rialto (you know, the revamped Robin!). They looked to be identical to the Renault units BUT have a polycarbonate backplate, so no rust! I've since checked out a few Rialtos and some, but not all, do have this lamp which to me looks to be a dead ringer for the Renault unit. The Ebay seller wanted £8 as a start bid: even if you can't find them on there it may be worth trying Reliant breakers, dealers, or anyone else likely to have bits of Plastic Pig lying around :)