When I advertised some Fulvia parts a few months ago there wasn’t much interest in the old headlight units that needed re-silvering. This was despite new Valeo units now being unobtainable, or only at a very high price. There were some posts on the forum about this at the time. I was pleased to sell two units (thank you Ben!) and I am pleased now to have sold the three remaining (two concave, one convex) to a member in Australia. Apparently, there is a firm in Aus that does a complete re-silvering service including separating glass from reflector. I don’t think there is a UK firm that offers the same service.
The Australian company is Décor Engineering in Victoria:
https://www.decorengineering.com.au/ - their prices sound quite reasonable – about £55 per unit. And the costs for shipment to Aus are not horrendous – my big 7kg package (including other parts) cost about £50, including insurance.
Not that it’s going to help finding spare units, but I was interested to see at the recent London Classic show yet another Gulf Porsche (?) fitted with Sport type concave units!