Peter Burrows’ idea of having a 120 mph dial made is good but I have no ide who makes these reproductions. I just see them on eBay. The seller who provided me with the 120 mph Corbin reproduction dial I used in the GPS prototype said they were made in Australia.
Also, I would expect demand for a GPS “Corbin” to be very low. I have no plan to make them for others. Though my blogged instructions are very long, the actual work needed is simple and, now that I went through the prototyping, should be fast.
At less than $600 for the parts, if you have the tools just make one yourself if you want one. Or work with a friend on making one or two.
Bob