The Bushman story is a little more complicated than is often thought.
First of all there were Bushman models and Pastoral (export) models with small differences.
It started with the D10 which had the four speed engine in the ‘short’ frame with 19” wheels front and back but kept the lightweight forks and the standard battery, two switch electrics. Gearing was standard
The D14 and B175 models had the heavier forks, different centre panels and, depending on export or home, energy transfer ignition, Vokes air cleaner and other detail differences.
Be warned, there are a lot of pretenders out there and even some of the genuine Bushman frames are not kitted out with all the correct fittings, which is fine so long as the vendor doesn’t expect to pass it off as “genuine” or “original” together with a stratospheric price!
If you do go for one do your homework with a parts book in hand!