Emhar on top, Master Box on bottom.
The MkI and MkIV used the same engine and transmission, therefor these should be identical from the sponson opening rearwards. The Master Box is accurate in terms of where the gear spindles (the four circles) are placed; the Emhar is off.
Ordinarily I wouldn't bother to correct the Emhar, but I may display this one alongside a MkI, so I thought I'd experiment. I used Oyumaru to make the mould.