I'm assuming you are looking for personal recommendations as Google throws up loads up and down the country
just phoned the company that does my head work. Auto head recon inverness.VVGood. they dont do it as such, they send it away to a company in wales. he wouldnt tell me the name as they dont deal directly with a regular punter. two prices. 1 for plating only and one for welding then plating. you could send it to them.
Capricorn engineering are probably the top place in the UK. Do a lot of F1 stuff, and used to charge accordingly.
Langcourt were my go-to since early 90’s when I was racing an RGV250 so I got to know them quite well… They have been doing Nikasil since Nikasil was a thing. Perfect job every time and rapid turnaround at good price. That they are still the place to go. 30 years later probably tells you something. Not in Scotland, but being in the game that long, they can probably add a cross-hatch to match your own tartan if you want !
I believe, they just send to Langcourt. IIRC correctly there are only 2-3 companies in UK doing the actual process....
Plenty of firms who say they offer a service, but actually send the work off to Langcourt. Or you could just deal with Langcourt directly yourself. Like I did.