Really interesting, it may help reducing the kick from the gearbox slack !
For the rear sprocket it is the same as sprockets from Marzochi racing wheels, you can find the specs easily. For the front it is trickier, you can either go for a JFT1439-14 fro ma Suzuki GSX-R250 RK 1989 which is not a perfect fit but works ok or the best would be to send them your sprocket so they could reproduce it.