Hi TJS
You answered my question and more.
My measurement of 80mm was the depth from your starting point in "ref photo rsprocket 2" To the top of the hub where the bearing seal this and not the sprocket.
After all components were fitted on my axle I still had a gap and as I can’t be for sure my 5.5 wheel is off a 750/1100 gsxr or year (you can’t always trust what a seller is telling you? as he didn’t know the different between 4.5 and 5.5 was!)
Its seam Suzuki fitted different sprocket hubs at times I was wondering if this is why there was a gap.
I wasn’t after the measurement to the sprocket itself (oem 70mm) but this answered my question anyway, along with the ref photo "rsprocket 3". I now known our hubs are the same too, Well not at the moment' I’ve still to get my hub milled,
it’s hope too known you had 3mm milled off the hub.. ref photo "rsprocket 1".
and that the gap is again no problem once tighten-up.
I hope all the above makes sense to everyone!.