I own a De Vere 54 - I am not sure when production ceased, I think in the early 1960s. The main agents for De Vere in the UK are Odyssey Sales:
www.odyssey-sales.com
I have bought a new helical-thread lens mount from them, they might have a carrier. Quite a few people have been junking De Vere 54s lately (for no good reason, they are well-made and entirely usable) so if you put a want ad in all the places you can think of, some one may have one. The particular example I have was given to me free. It came with a condenser head (which several people told me was tricky to set up, and which I sold on) and also the original cold-cathode head, which almost gave me heart failure when I saw it (would you believe a hollow water-filled perspex diffuser from which half the water had leached away?). In the end I got a third-party cold-cathode head for about £35 which works fine but whose light is too blue to use with multigrade paper. An Ilford multigrade head would be ideal for your De Vere, of course you could retain the head if you ever changed to another enlarger.
Regards,
David