I finally got the gear assembly back in place and the whole mechanism in the box. But the gearing is the least of my problems. Because it was adapted to 45 rpm the tone arm settings are completely wrong and there seems to have been some creative adjusting taken place to allow it to play 45s in the first place. I now have to work out what is missing and what was never the way it is now.
The W1100 must have been a wonderful machine when it was new and all tuned up. The mechanism is as robust as a steam engine and about as dangerous if you get your fingers in amongst it all.