I spent a lot of time reshaping the FERC so that it would fit around the swinging arm, and I'm pleased with it now.
Trouble is, I didn't realise that to get the front section on, the rear has to be off:
And, as if to rub it in, you can't get the rear off with the shock absorber in position...
When it's back together I can trial fit the inner primary chain case.
The front section of the FERC has a captive nut to attach to the inner primary case.
A small job coming up - remove the broken case screw:
While I was poking around the rear end (and wearing working clothes) I used a crayon to make a mark on the swinging arm, with the mudguard, centre stand and oil filter in place. This was where the swinging arm grease nipple would go.