OK, grounding tab of transistor (Q34) with game on and test button pressed once (per Clay's guide) coil fires , so must be one of either Q34 ,  the pre driver transistor (Q33 the game tells me by running solenoid test on S23 and pressing start button) or the  related 74LS374 .

Any which way looks like I have to pull the driver board out and guess I will replace both the TIP102 (Q34) and a 2N5401 (Q33) .

Be good if I can fix this myself