a number of my bikes are happily running 9-spd, however a stick rear mech interface has caused some issues.

Can Shimano 10 Spd Shadow+ Rear MEchs (the ones with the clutchy thingy ma bob) me used with 9spd shifters?
In theory the mechanical leverage of the 9spd shifter should allow it
but Shimano may have altered something to prevent this?? any one tried it before I hit the buy button.

No, they have changed the actuation.

Can’t be done. Can be made to work with SRAM 9 speed shifters by use of a spacer. Bit of a bodge, but works well by all accounts!

So does that mean there is no Shimano 9s compatible clutch-type rear mech out there?

I have a shimano 9s shifter, a perfectly useable cassette, a spare cassette and a couple of spare chains, so I want to keep everything 9s, with my Shimano shifter. However, I need a new mech. Is there no clutch solution out there that allows me to keep my 9s cassette and shimano 9s shifter? 🙁

Is there no clutch solution out there that allows me to keep my 9s cassette and shimano 9s shifter?

No

He’s right.

Ah-ha! There is a solution here (luckily I can speak some German), for €15 someone in Germany modifying 10s mechs to 9s actuation:

http://bikemarkt.mtb-news.de/article/42978-umbau-shadow-plus-auf-9-fach-kettengluck-2-0

Of course, this is also someone doing it in Germany…. No-one doing this, or offering any sort of adapter in the UK? I can’t find one.