For my Texan, I basically started out with Ken Uhrig's old Harvard Mk.IV model
(once again, all the background info is here on my forum:
Uhrig's Harvard and Dave's Harvard redesign)
so, not being an expert on these planes or their differences
I didn't really want to get into the variants or earlier designs.
The main visible difference for the inexperienced is the rudder/tail shape.
There are also some variations on Canopy design.
And it looks like only the Canadian Harvards had the extended exhaust (cockpit heat).
Other than that, I am ignoring anything else and avoiding any major variants.
And because of the situation (or lack thereof) with Ken Uhrig,
I don't want to start pumping out Harvard models.
Out of respect for a fellow designer, I will stick to the Texan brand for now.