It can be added after the mantlet and barrel has been assembled...very carefully.

The slop deal on the main gun is always a pain in the tail. I have been known to glue the clutch gear in the elevation unit and use a very strong spring to stop a lot of the play in the main tube. I have yet to try a servo, but that should work well. A mini servo will fit most anywhere. Part of the problem is the long and heavy main tube, and any play what so ever in the mechanism will be amplified.

As for the collection, the T 34 and Sov Panther belong to VCO, my charming wife. The other three are just part of the total zug floating around the house. Thanks for the compliments!