According to the Scalemates time line for the 1/72 scale 2145 kit , it doesn't base on the SH kit but on the Eduard 2142 new tool one. Also the same is with the Eduard 2143 and 2144 that got the new parts for the correct varinats of the Bf 109G. So the Gustav kit series has nothing in common with the SH kits. As far as I know the Eduard 1/72 scale models are their resized down 1/48 ones. The SH models that were designed with the Eduard togehter are for the Emil series. Therefore both the SH and Eduard offer the same Emil sprues although with different addtional parts and markings for their own sets.