The execution looks quite good, and I'm sure with more builds under your belt, you'll want to try some weathering.
You should check out Mike Starmer's work on British vehicle colours:
http://www.mafva.net/other%20pages/Starmer%20camo.htm
In his research, you will find that the caunter scheme was no longer to be applied to new vehicles as of October 1941, with the provision of one disruptive colour only. So Stuarts could have the proper three colour scheme, just depends when they arrived. During the Crusader battles, the latter was probably more likely, but one can't be pandemic about this, as it was war time and repaints can't be assumed to have been implemented immediately.
regards,
Jack