https://www.youtube.com/watch?v=xos2MnVxe-c
http://suzaku.live-evil.org/0307252316b.jpg
After replacing the main pi filter caps this week, I decided to risk powering it up slowly with 2 new 5U4GBs, and after a while when voltage seemed stable and one paper bomb exploded someplace, not sure where yet I decided to hook the scope up to G1 of the horizontal output tube, well one of the pairs...
https://www.youtube.com/watch?v=NmPhaG1ud38
All the critical bits are working!
I can now move on to making it good as new!
Furthermore the broken core Merit hvo-5 came today, and my guess was right, it's physically identical to the FBT in the chassis now, meaning I can swap the broken bits from it to fix it, most likely Merit made this FBT for maggie in the first place.