1098 gearbox woes

I've got a 2007 Tricolore that, today, decided to not give me any gears and makes a terrible crunching noise. Bugger.

* I've had false neutrals for a while (actually for ever, really). And today caught one between 3/4 or 4/5 as I was doing a clutchless upshift at approx 7-9k on 3/4 throttle. A quick bang on the lever and it went it but mad quite a "bang"noise.
* 5 miles down the road and coming down from 4 to 3 it made an horrendouse noise and I sort of lost drive, then gained it back again
* I replaced the clutch frictions a few weeks ago so thought it might have been that and pulled the the clutch in but that made no difference at all
* I was doing about 50mph down a hill so just killed the motor as a precaution and coasted to stop
* Even when coasting with the motor off it still made a rather unpleasant noise but didn't seem to lock-up the tranny
* I pulled the clutch at the roadside, all fine as I had only a multitool on me I had to call it a day and get it lifted home
* Before I did that it seemed to have found, or I found, a neutral but probably a false one as the neutral light wasn't on
* Then starting the bike with the clutch in was fine and it even pulled away slightly before making a grim crunching noise so I killed the motor again

I've read loads about false neutral, bent selector forks and broken return springs but most of what I have read doesn't "seem" to exhibit similar symptoms.

Thoughts and ideas folks?

(I'm pretty ok with mechanicals so happy to tackle a g/b change and/or rebuild unless it's a bit specialist/risky/needs daft tools etc.)

 

Ok. Off down my own route for the moment. Going to take the engine to Ducati John so he can strip it and see what the craic is, so started to strip the bike down, pretty straightforward so far aside from the the very wide selection of bolts, hex and other fitting the Italians decided to use to hold it together. It's now naked and tomorrow I'll be doing the final engine drop.