FYI
My boards had multiple issues, so I sent them to Clive. The boards are no longer stuck on Spanish, but I don't have a root cause as to why they were before. The clearest indication is the game ROM, which Clive replaced. Unfortunately he didn't send back my old ROM so I can't swap them out to test.
Clive's response on replacing the game rom:
Some of the 'aftermarket' ROMs seen at the shop in boards from customers have had faults as most are re-used (erased then reprogrammed) ICs and not tested in boards prior to being sold. The ROM was replaced to be on the safe side.
List of what was repaired:
WPC-95 CPU board (AFM, Ser# 50753102494): New 84-pin PLCC ASIC socket. Cleaned ASIC. 74LS14 IC (U5) and 14-pin socket. 4.7uf/63v/105c (C73) and 2x 100uf/25v/105c (C22, C31) capacitors. MC34064 Reset Supervisor IC (U10). ULN2803A IC. Attack from Mars version 1.13B Game ROM (NOS 20C080). Reflow all headers, RAM, ROM microprocessor, PIC, U23 and ULN2803A sockets. Added remote battery pack system.
WPC-95 Power Driver board (Ser# 53341102290 with previous repairs): P600D rectifier (D21 -- excessive voltage drop). P600D rectifier (D11 -- showing heat damage, changed in prior repairs). Fuses checked; -- F104 (4 amp), F108 (6A), F109 (4 amp ) slow blow fuses due to incorrect values installed. ULN2803A IC (U3) and 18-pin machined socket (due to high failure rate). Filter capacitors measure; 2x 100uf/50v/105c (C1, C40) and 2x 100uf/100v/105 (C22, C23) due to being out-of-tolerance. Removed wired links from GI area and installed 8x zero ohm resistors plus 6 traces patched. 7812 voltage regulator. J101, J103, J104, J105 and J106 high temperature headers. Various points reflowed.