First start of the motor didn't go so well. First problem (amongst others) is a knocking sound that appears to be coming from the starter.
I removed the inspection cover and sandwich plate, spun the flywheel around and inspected the teeth. Attempted to shim the starter as per some suggestions on other forums. Still the knocking persists. The starter was recently rebuilt. I uploaded a vid to show it.
I'd replaced one of the torque converter bolts due to it being damaged during the initial engine tear-down. The flat washer I used with the bolt was too thick and the head of the bolt was just kissing the starter as it passed underneat. Removed the flat washer and just used a spring washer and thread locker. Fixed.