OK, for starters he says he will not send out of UK. You may be able to deal with him, but I doubt it.
Second thing. There are two types of that Tamiya Transmission as far as gears to. The Type 2, which was not out long, has black plastic gears near the motor, under the cover. The Type 3, which looks the same from outside, has metal gears there. Other differences is the final output shaft length, shortest is Sherman, KT and Tiger 1 is about 2mm longer, and Panther is way longer.

Yes, the gears will fit all Type 2 and Type 3 transmissions, but without seeing the rearmost gears under the black cover, I can not give you a definite as to which it is.