I found one YT build of kit 6268 which said the the radiator fan assemblies for left and right were the wrong way round, so thats parts D23/D2 + D24/D3. Even if the instructions are correct how are you supposed to tell which goes on what side of the lower hull?
If you are building an early G with zimmerit use the many bladed fan, part D21.
If you are building a later G without zimmerit use the fewer bladed fan, part D5.
The reduction of the number of blades was an attempt to save raw materials as things got desperate in the later years of the war.
Thanks I am making a late version, from what I have found online it makes a very good representation of a M.A.N machine as found on the prouction line in April 1945 which has lovely 1/35 scale drawings on pages 200-203 in Panzer Tracts No.5-3.