The Rubicon T34/76 kit contains a number of optional components. Once you have chosen the version you are going to build you have a number of spare bits. Unfortunately you cannot assemble an additional turret (though there is another complete 76mm turret in the T34/85 kit). In the T34/85 kit there is a spare lower turret ring so you can assemble most of a second (or third really) turret complete except for part of the mantlet.
The spare ring from the T34/85 kit is bottom left.
Scaling exercise for a 76.2mm round (a Warlord Marder III crew man).
Receiver in place in the turret.
In detail.
Sight assembly.