There were quite a few differences between the original 4-cam 4-cylinder cars & the later 6-cylinder cars but many have been modified/updated over the years - for instance the museum car shown is an earlier 4-cylinder model with later rear bodywork (with the larger 'elephant ears' air intakes).
The car shown in the original post looks like a Beck replica.
Here's my Martin & Walker 904 replica (not completely finished):
