Hello Bill, a possibility is Pryor in Sheffield.
Brian
Thank you Brian. I will follow up that lead.
Thanks for the link, Michael. Yes, their existence at least gives me hope that they may be obtainable here in the UK and possibly at a more modest sum than $240.
Vintagengineer, thanks. I had a look on Ebay and there is a serifed set currently up for auction but it is missing letters c and k. For the present job I only need two letters and, as luck would have it, one of them is c!
ETA: I have put a photo in my album of the lettering I want to duplicate. The tools are the bronze ones I mentioned in my opening thread. The picture actually shows straight-line tools not the gouges (i.e. curved tools) originally discussed. Both sorts are made by the same maker, though.