I have been in that shed again and found some unused 1960's fixed wheel cogs mostly Cyclo made. They are £4.00 each plus postage. This should be quite reasonable as they will go in a stout envelope. 3/32" 17 and 21 teeth. 1/8" 16, 19 and 21 teeth. Please contact off list
Best wishes and be lucky. Michael Butler Huntingdon UK.