I haven't been following this thread ..... but I wonder if anybody has considered a reverse turning starter and putting it into the flywheel from the other direction like Subaru and VW.   There are a limited number of starter gear pitches, and I have installed starters on a number of engines by simply putting bolt in one hole and rotating the starter until I satisfied with the gear mesh and drilling the second hole.  Depending on what sort of redrive is being used this might be a solution for some people.   Just thought I'd toss that one out there.... I suppose someone has already done or suggested it.

H.W.