You could get a standard stainless handle, or dig one out if you already have one, and get it covered in black Guncote or similar. There are several firms in the UK that do this sort of work, mostly on firearms. It's very a very tough finish and looks good to my eye. I had a Weber Bulldog handle finished in blue Guncote five years or so ago and it still looks flawless. Unfortunately I can't remember the name of the bloke who did it.
I think your best bet is as per @Sconehead's suggestion. There is another firearm coating product called Cerakote, but the people doing it are mostly gunsmiths, and it isn't cheap. The other processes are blackening and anodising, but I don't think the finish on either is especially durable. Blackening, or "black oxide" process, is that used on the Blackland razors, and the USP for that is that the finish wears and ages nicely (it does on mine).
Maggard in the States have a couple of black stainless handles at $19, and West Coast Shaving sell a range, currently about $16. At those prices you might just get it here without the VAT/RM import caning.
• High quality razor handle• Stainless steel construction with black coating• Textured handle for grip and beauty DescriptionSince 2007, West Coast Shaving has been meeting the grooming needs of discerning men with luxurious, hard to find, and bestselling items. We are passionate about seeing a...
Thanks for all your replies so far and appreciated
I will look at the 'ready made' leads, but will also ask a local small company over in Liverpool who does specialist coatings as I have a spare ATT Colossus. I use him now and then for powder coating and he is first class.