In one of the pics above you can see the stock top and rear covers, too high and full of holes... After sanding my MDF mold I primered it and gave it a quick layer of paint to help find any imperfections. The left side looked okay but the right side looked a bit wavy. After holding a ruler against crankcases and MDF mold, I found that the "wavyness" started in the right side of the crankcase itself.

I drew a guideline on top of the crankcase and used a beltsander to knock down the high areas, then using the corrected crankcases as a guide I reshaped the MDF mold again. There were still a few low spots so I used polyester filler to build up these areas. While I write this the paint is drying on the mold and next week I should be started on the sheetmetal version.