Kevin
Best source of advice would be the holbrook group on groups.io. Easy enough to sign up and add pictures.
Generally a B8 will have an open belt headstock whilst a C8 has a geared one. Officially the C8 was only made in electronic drive version sitting on a huge cast iron base.
The original stand for a B8 has a cast plate carrying the B8 identifier on the fast / low speed selector.
I have seen a geared headstock "C8?" factory made for bench mounting without the electronic drive. Whether that was officially a C8 or a B8 I know not. MoD Establishment machine.
Clive