I have...a cunning plan
This looks very dodgy but is actually pretty strong. With some reinforcement on the front face of the servo and standoff sleeves at 4 x opposite points it could work nicely. The stand off gains 15mm so the M/C would only need 10mm trimming from the end of the plunger. I'll be spinning the Servo 90 degrees anticlockwise so I can mount the M/S the right way up and keep my reservoir
This all of course depends 100% on the assertion that the M/C and servo don't need an air tight seal because in this case, I think I'd struggle to make one
As far as I can tell this also will not cause the M/C to foul either the side panels or the bonnet (thought the latter is guess work). If one of the other builders can mock up the same thing and make a few measurements this may be some way to the solution