I have a drawing of the boss but the bolt holes for the scuby crank are offset, the PCD is the same for all the holes but there is one pitch between the holes larger than the rest. I used the original scuby flywheel to drill the holes in the boss, well to mark the correct positions. I have opted to use a 5mm aluminium adapter plate, this should be OK but if you want to use a thicker plate them the boss would have to me amended to ensure the starter ring gear matches with the starter. The clutch is from a panda I think, I will check and post later. I have taken some more photos and will upload later, as my computer is down. I am attempting to use the 126 starter, but have been told it may be a bit on the light side so I am trying to get hold of a cinq starter in the hope it is an easy mod to fit. One problem is the bolts which hold the scuby flywheel to the crank are 9mm x 1mm pitch' you will have to have these made as this is not a standard size. You can use the scuby flywheel but you have to make an adapter plate to suit, look at light aircraft mods, this engine is very popular with home build light aircraft protects. I made a plywood template for the adapter plate and transfered this to the aluminium , if you would like I can trace the plate.
Ralph