Some more pics of the adapter in situ...
First the 50mm macro snout! You can see the control knob is nicely placed.

The adapter is the correct length to allow full extension (close focus) of this lens.

The gearing works correctly to allow manual focus but with the 50mm only allows fine adjustment since the oly gear has end stops.
Fine for photos since AF can do most of the work but I shall need to come up with a custom gear for video.
(n.b. it takes several full rotations to focus the 50mm infinity to close - and it is velocity sensitive too but you don't get much speed up on the knob)

On with the dome - it actually goes on a few more mm than this pic shows and closes up the gap you see here.
But then you have to re-adjust the petals and I couldn't be bothered for this little shoot

From above

The lovely 8mm sitting where it should

Now the 11-22mm with "customised" (draught excluder) gear from a 7-14mm.
A bit tricky to assemble as the knob has to stay in it's pulled out position.
But it all works as it shold which means the even larger 7-14mm would fit in this rig too.

With dome and per-02 extender.
I do not think this is at the nodal point at all and need to get a per-01 instead.
However there is no vignetting from the dome so it is worth testing in the water.

And finally the lovely leak light showing I am leak free

Simon