I stripped own my recent purchase of a regular Noir & found a lot of coke slim under the speaker pods when I removed them also a lot of dirt under the speaker grills.
You may have a lot dirt dust under the psu tray.
I too was wondering if you could just drop in a LED tube as on my Lindy you had to remove the starter otherwise you would get flicker, the flo is working for now but it must have the starter built in to it, it was a NEC unit.
My lit instruction space led's are mostly gone but I could easily replace them with some eBay jobbies.
My cabinet Royal fan (very expensive to buy new) was too noisy to use but the lcd panel ones are ok.
If these cabinets are going to do SF6 duty long term, you might want to get 7 or 8 button panels. I know it's a little late for the suggestion for this weekend.
I had 6 buttons set up on my Vewlixes and it was the first complaint I got when I had people over. At least the Vewlix panel has a 7th button hole and that seems to be enough for most people for DI. I'm not sure if Type Arcade has officially released yet, but in the early trade show pics the panels had 8 buttons.