For anyone who ever wondered this is how this one turned out.
Though the gearboxes are identical except for the final ratio, the V6 and 1.9 JTD bell housings are different ( or mine are ) not just in the fact that obviously they have to join to different engines but also the V6 has a hole at the top that allows you to see the clutch bearing engaging and the JTD doesn't. they both have the hole down the front side shown on my last post.
I was never able to get a good picture from my cheapo Aldi borescope to save on here but looking through it told me the inside of the bellhousing was fairly clean so I decided there would be little point cleaning the friction surfaces of the clutch even if it had been possible.
Having considered DaveAlfa11's advice for a long time and read the stuff he mentioned, and a lot more including for the same engine in (spit!) Vauxhalls, I finally went for the solidmass conversion just for the experience but the simplicity and lower initial outlay did play a part as I had a V6 clutch kit in the garage already.
A year on I'm fairly pleased. traffic jam driving is slightly less relaxed as common sense and good advice said it would be (I don't like to put it in second and let it haul it's self along at tickover anymore) but not to the point it ruins my day or makes me worry for the engines health. Extra urban is just the same as it always was.
Long term engine life remains to be seen obviously.