Yep - it's another boring old character designer program.
Letter Set is easy enough to use. Working on a drawing-board sort of basis each letter comes up on screen on an 8 x 8 grid, and can be changed by moving a cursor to build up or remove part of the letter. Using the program is a bit tricky at first, but once you get the hang of controlling the cursors, it's very quick. And once you've re-drawn the complete set, you can load them on to tape, and use them whenever you like.
Label: Alpha Computer Products (193 Brampton Road Carlisle, Cumbria, CA3 9AX)
Price: £3.50 (tape), £5.25 (Microdrive)
Another character designer; but reasonably cheap.