If you invert that amp the LCR cap will be upright and all hell will break loose when you put the dust cover on.
As far as storing your 45s globe down who is to say which way they sag?
For an expert opinion I suggest you contact our esteemed vacuum tube expert in Maine, Mr C.T."Bud"Daniels.
After he gives it carefull thought follow your heart.
Mike, in all seriosness if you are worried about sag in your 45s then you just need to buy more and keep them rotated. A graph next the to tube cave where they hang upside down can help you keep track of the hours on the pairs.
I am so sorry as I know you are really worried about this and maybe rightly so but they after all just tubes. If they start to sag in middle age then no wonder they sound so lifelike.
As I continue to dig a deeper hole for myself just remember it is only HiFi and a hobby and that day when you find a box full of 45s remember Thor and give me some anyway.
Your Friend,
David