Hi Toni,
A nice kit indeed, allthough i't lacks some details and... it has only 10 instead of the 12 wheels. But if you want Armo has a nice and effordable replacement set.
I've build this one also, but it all went wrong when I wanted to strip the paint (I didn't like the result), and the plastic was disturbed by the brakefluid
So I'll have to buy a new kit and start all over again...
Eduard has a nice PE set, and allthough it's mentioned for the BA-6, you can use some parts of it, especially the all-terrain tracks, very nice!
One last point: the vehicle is too high. I mean the space between the wheels and mudguards is too big (refer to your images), but you can change this easily. The solution is to cut the internal part of the mudguard until they comes at the same level as the floor. you also need to reduce the high of the frontal axle by sanding the suspension a little. And at last the turret is placed too far at the back of the vehicle, just move it 1,5mm to the front
But let all this don't scare you, these are all easy adjustments that will make your model look much better.
If you need some reference pics, look at thetankmaster.com.
If you have any questions or need some help, just ask and I'll try to help you.
The BA-3's were used trough out the first half of the war, even the Germans did use the captured vehicles...
Here's a picture of my BA-3, before the adjustment of the height, and before it all wnt wrong with the painting...
Good luck and greetings,
Hugo 'Beaker' Luyten