I'm trying to talk my wife into it Jonny. We'll see. I think If I had just picked up an RS instead of a JS in the first place, life would have been much better.

I think a spacer under the layshaft might be a good starting point though as it would add slack to both the center and front belt and take the tweak out of the front lay shaft. If this solves it, I'm going to be extremely happy. Then I'm going to recommend that someone put out full size shims for that front shaft holder (or just ignore the placement pins). The next logical step if the spacer works would be to replace the two cast pins with set screws to adjust the for the required depth depending on shim height or maybe just to hold the shims in place. if the front belt is perfect and the center too loose initially after shimming, that's fine, then I'd actually be able to use the center belt tensioner.