After initial setup on Thursday the game was running OK.
On Friday morning before opening the game has lost sync and wouldn't adjust to lock. I had a spare Money Money PCB to swap in but even with the game PCB replaced there was still no sync lock, suggesting a monitor problem.
With no spare Hantarex MTC-900E/USA chassis to swap in the game was withdrawn to the dead zone along with its brother :(
I'd already seen sync problems as a result of bad sync input transistors so I started off suspecting them. A spot check of IC2 (TDA2593) pin 6 matched waveform 3 in the manual OK so attention turned to the sync input transistors. Looking at TR2 (BC237) with the scope suggested base & emitter were OK but very little on the collector. SP13 had a 200mV signal offset at +8V and drop of freezer spray on TR2 caused the signal to jump to 400mV. Replacing TR2 fixed the sync and the chassis ran on the bench for a few hours with no further issues.
Reinstalled back into the cabinet the picture looked good and the game ran for a few hours with no further issues (the front was still wedged & wrapped from the show, hence the reflection letterbox photo).