Since these lights have nothing in common on the board, nor different from the working lights, it almost certainly has to be the power daisy chain to those lamps. For example, looking at J1 on the lamp driver board, there is a combination of rack and target lamps going through U1.

But what is in common with the target lamps, left ramp (?loop?) and the Deluxe lights (those in the backbox?)? Those appear to be three separate sets with nothing in common.

I agree with BigAl, that the first step for me would be to confirm that any of these lamps light when the control side is grounded. I would pull J1 off the lamp board, then turn it on and try grounding the pins. 14, 15, 16 & 28 are for target lamps.

A weakness of the Bally lamp circuits is the ground. Pins J4 - 12, 11, 1, 2 burn up regularly. On the Aux board, those are pins 13, 14, 15. But they will affect all the lamps, not just this group.

The 6.5VDC comes off the rectifier board directly to the backbox and cabinet. So all lamps would be affected if it were there.