Model 131

Will there be a T-34/76? or KV-1.

Model itself appears well made same with the Panzer

T-34 - Yes
T-86 - Probably not, one can just upscale the 34
KV-1 - Nah

Total list of project tanks
-T-26
-T-34
-KV-2
-Panzer 4 (Snub-barrel)
-Tiger 1
-M4 Sherman
-Calliope
-Slugger
-Renault
-Cromwell
-Churchill
-Whippet
-A7V
-Tzar Tank
-Mark 5

Does not include lighter vehicles, aircraft, ships, or artillery pieces

T-86? Do you mean the T-34/85 (aka T-34 but 4239482394239 times better)

I noticed that the Germans dont have a low teir tank, for that you could use the Pz.Kpfw. T 15/Pz.Kpfw. 35 (t)