(a) the same people who would make it up to go on the transom, i.e. signwriters or
(b) stick on letters from the hardware shop or swindlery. The latter last about 1.25 seasons, in my experience ....
You can get them at local DIY shops (think they have stopped at B&Q) - we found a local DIY shop selling different coloured letters and in different sizes
I have just had new boat name stickers made up for the transom on my boat by Joe at Mediaink, cost £15.75 inc delivery for 3 lines (boat name 1000mm X 90mm and home port/ssr smaller).
No connection, just happy customer
Have a rumage on this Google page. There are lots of places in Brighton that will produce these for you, they will look smart and professional. Modern vinyl letter graphics will last for years even on a boat.
We have used 'Topcat' graphics and been very pleased. They do specially shaped ones to go on lifebouys and they advertise in PBO etc. No connection except as a customer. Their address is:
Topcat Graphics
3a High Street,
Much Wenlock,
Shropshire, TF13 6AA
You could get some right colour contact paper from the hardware. Print out what you want on the PC in whatever font you like and the right size. Stick the printed paper lightly onto the contact and cut through the two with a sharp craft knife. It will take a bit of practice to get the cutting pressure right. You want to avoid cutting through the backing paper of the contact. Weed out between the lettering. Stick masking tape onto front of letters to hold them together. If its a small job just pull backing paper off sticky back of letters and carefully stick them onto the horseshoe or whatever. The glue can be cleaned off with some white spirit on a cloth.
For bigger jobs like a boat name you will have to make a masking tape hinge so you can position the lettering before you pull the backing paper off. Proper sign vinyl tape is a bit stiffer and easier to use than contact. Practice a bit first and you will get professional results. I used to work this way before I got myself a cutting plotter.
I am presuming so, as thats where I got my last lot for PUFFINs lifebouy. In any event, I find it hard to believe that legislation now prevents the sale of self-adhesive letters and figures. I can buy them in a local 'Pound Shop', for -yes £1 each.
I printed them out on the puter and cut them out. Then drew around them onto acrylic which we had in for building covers etc. A little evo-stick and they are rock solid.
I considered giving them a little curve but it was too fiddly and I wanted them to clear the brackets. If we had a single barrel name I would have definitely added curve.