I got around the problem last night by modifying a 12BA screw and soldering the etched covers on, making a small bush from tube threaded 12BA and a small spacer. Once I get them assembled, I may not need the spacer but if I don’t they will go in the spares box.
David Andrews Princess Royal Return Crank and eccentricsDavid Andrews Princess Royal Return Crank and eccentrics – Constriuent parts
I still need to add oil corks to the eccentric rods.