Oh, sorry. I am in the US, thinking of buying a UCE, and am interested in rear tail lights, tan seats, pipes, and rear luggage racks.
First, the UCE is made to look old, but it is NEW. I get parts from shops that carry Parts Unlimited and Tucker Rocky catalogues.There are custom applications places like AirTeck and Benjies. Google the specific part you want or look for cafe racer, and Brit Bike sites like Triumph Rat. Advrider has an Olds Cool department and Cycle World Forums has an old bike department where people can refer you to more specific sites. Probably a lot of others, too.