The lock relay should always be energized.
The chime circuit is simple. The chime is energized by a switch on the 100 or 1000 point relay.
Move the relay by hand to the energized position with the machine off. Make sure all the switches change state.
There is a manual for Jubilee on ipdb.org, it shows the relays and all the switches.
If the game has a score on the 100/1000 reels on startup does the score reset?