The bushes worked perfectly. I may need to source softer springs for the Konis eventually but they can be run on minimum preload for now.
Another minor victory has been reclaiming the very worn remote gear lever/pivot (all 2Cs seem to suffer from it). Drilled out the lever to 17mm and pressed in a plain bush acquired from Simply Bearings. Much better with minimum sideways waggle. Might have been better if the factory had used a replaceable bush in the design but what do we expect for a bike clearly built to a budget?
Currently attempting to refurbish a 125H petrol tank (thanks for the idea Evguru). It came from Italy in a very sorry state but at a reasonable price. A fair amount of time with powered abrasive devices will be required and the odd pin hole filled with chemical metal then a simple coat of Hammerite smooth red by brush will do for now. I might even treat it to badges as I already have one going spare. As hoped, it fits on quite well with a long bolt through the bushed mountings and the holes where the tank rubber mounts are on a 250 frame at the front. It will need the rear rubbers notching (well something similar and cheap) to sit nicely but a vacuum cleaner drive belt will retain it in the usual manner. The run for the throttle cables, particularly the front is a bit close to the tank bottom but I can probably get away with it by adjusting the 'twist' on the carbs within sensible float bowl fuel levels and careful routing. Not tiny but significantly smaller than a 2C tank and more in the spirit of the project than some new pattern tank off something not Morini.
I have a cunning plan for the seat. The 2C one is in surprisingly good condition but rather heavy, and naturally, longer than required. The plan will involve a genuine MotoMorini part but I won't say exactly from what machine in case the NHCA Forgotten Era organiser is reading this
Time for the engine swap soon.