After I posted my question I realised all was normal so went ahead and plugged in CPU board and game booted up normally (has an Altech MPU board, the other boards are originals)

Found a few problems such as i had forgotten to solder the wires back on the lugs for the drop target reset coil LOL

Downloaded the schematics and realised I have a switch matrix problem to track down because flipper return lane switches, outhole switch, left POP bumper and Grotto are not scoring and associated coils not firing .
All these switches are on the same column on the switch matrix so will look into that issue when i have some more time .
Also need to check Display voltage .

I'm happy that the game is close to playable now instead of being dead as a dodo the last 13 months or more.

I could well have a connector problem because so far i have only replaced housings and repinned the Rectifer board connectors .

Also have a cab repaint to do with this game too .