I would add that experience in swapping flywheel windings to other centres suggests it is worth noting the following.
The units are balanced so they rotate without significant deviation nor strain to the crank and bearings. Thus the orientation, normally offered by several pegs/dowels, should be adhered to. Be aware that it is wise to replace any iffy looking/feeling set screws holding the unit together, is it nine? I think they are BA type. Do not tighten too hard and ensure an even spread of the load, so should the centre fastening not be 'home' the screws will not shear. If one shears it can then withdraw from its hole and make quite a mess. If the lot goes, as has happened even on untampered with flywheels, it gets very interesting very quickly!
This said care should mean you can possibly salvage usable dynpostarts from what might appear a load of old rubbish. Never throw then away. If your not minded to try and repair them, trade them to a twit like me for some bits you can use, and we retain a pool of units to recycle. The stators will repair too, not easy but if you have the tooling and knowledge it is a nice winter job in the warm. I have a few sets of parts to reassemble but most of mine have now been done. I still have a new/reconditioned Excelsior Dynostarter with casing and points bits and a spare used flywheel. These are ex Dolphin Engines/Chapman stock.
