Seemed simple enough, take one Wico A, correct apart from drive dog and substitute right fitting from *vast stock* of parts.
The outer barrel of the impulse drive which incorporates the drive dog also contains the impulse spring and all the ones I had were anti-clock, but a little thought suggested that turning the spring over would have the desired effect. This was accomplished fairly easily using a jubilee clip as a compressor to get it back in. while I'm at it the pin on which the impulse catch pivots looks a bit worn so I'll put on a better back plate. Pop on the spring barrel and - why won't the impulse wind up? Ah, anti-clock back plate is different. Take it apart and put original back plate back on - the pin wasn't that worn. Ok let's screw it all together again - oh b****r there's
1/4" of threaded shaft left sticking out when the sleeve nut is tightened - now I'll have to take it all apart again and use another armature, what fun!
BTW. Anyone know when the ubiquitous Wico A was introduced?