Will try the chaps in Hereford.
What size/position you after?
Most shops with sprocket boards will only have the useless sizes left, which is why the others binned them.
That said, I have 2 tight ration NOS freewheels I'd like to make wider ratio. Maybe help each other out?
RY 19t, 3rd largest in on a 6/7/8 sachs freewheel. I have a board but as you say some of the useful sizes are absent. Other than straight through blocks (grrr) the only useful cassette i can build is a 12-21. Would like a 12-23. Lmk what you're after, will see what I have.