I suspected you might have installed a 3rd bridge - cool idea.
And thanks everyone for the advice to fix everything while I have the board out.
Again, I reiterate, I bought a kit which proposes to provide all of the parts necessary to de-populate the Power Module and to re-populate with superior/upgraded parts. Said another way: All old parts were desoldered from the PCB and replaced with new. For the most part, this kit did exactly what it promised.........with an exception or two.
In a game this old I think it's wiser to rebuild entire systems rather than to wait for problems. Since problems usually spawn more problems each PCB on this game is getting an overhaul.
I have replaced all components on the Power Module:
Diodes, Bridge rectifiers, MOV, Resistors, New fuse clips (high current and low current), new fuses, replaced all header pins male/female and their enclosures, re-pinned all connector pins male/female and their enclosures, every removable part was removed and replaced.
I have some new bridge rectifiers on the way since I had already mounted BR2 in the original spot by the time I took the photo and the leads were already too short by the time I asked for advice. I'll track down some heat sink material and copy your idea of top-mounting.
My current setup should last for the next couple of days until I can sit down and correct the issue. This machine sees about an hour of use per day on average in my home.
Since we've gone this far with the thread, I will post my "fix" here for review and critique.
Maybe this thread can help the next guy with his rebuild.