Just in case you thought the saga might be over - there is another episode
There was an unexpected hitch over the purchase of the Janome so I bought - instead - a Jaguar 099.
Its got a simple threading system and I like the fact that the whole front can open out to aid threading the lower loopers.
I've tried it and it seems quite efficient so far.
Its more money (£320) than the Janome but hopefully worth it.
The babylock is in the repair shop and we'll see what the outcome is.
If all is well, I'm mulling over whether to put the babylock up for sale after the service/repair. I never use any of its fandangled facilities (e.g, the WAVE stitch) and maybe happier sticking with the more simple machine, as I don't do so much sewing nowadays.