My search for a suitable blower for my PB engine rebuild continues. After careful analysis of the capacity needed my earlier search for a Marshall A75 has changed to a J100 unit in good condition (rotors especially). I have acquired a MK21 which provides the desired capacity but will be quite difficult to set up (manifolds, gear cover, etc.) so I am on a last ditch search for a suitable J100 before embarking on the MK21 fitout.
A MK21 fitout will require 3D scans, modeling (w/ adjustments) and printing of the final parts (manifolds and gear cover). This can be done more reasonably these days, but will still be challenging. If anyone has had experience with this pursuit I would be interested in comparing notes.