Still waiting on a back winging its way from Germany to put a roll or two through it but it would appear that the sync modification was added much later - seems to successfully trigger electronic flash (and the flash is visible through the lens at 1/200) so all being well that's a nice addition. Sadly still having problems with V selftimer though. Any guidance on how to safely disassemble the lensboard and shutter to flush out and lubricate where necessary (Found a teflon based dry lube is effective on shutters intended to run 'DRY').
I've got a copy of the Compur service manual for their shutters, so once I get to the shutter it's fairly straightforward. It's just getting to it that is proving somewhat problematic.