Great job RM. Others are surely thinking of this, but I will just come out and say it. If given a choice of only two Soviet ACs to be produced in plastic, the majority that I know would have wished/wanted:
1) BA-10
2) BA-64
That being said, the BA-3/6 is still a welcomed sight! Especially if a gamer is putting together a Finish army because a few captured BA-3/6 ACs were used by the Finnish Army.
Side Note:An interesting note to make is that later in the war the BA-3/6 and BA-10 ACs were gradually replaced in the Soviet Army by T-60 and T-70 light tanks, but the BA-64 AC continued to soldier on (being manufactured and used) until the end of the war.