Pics:
Test frame, a lot sturdier than it looks, really rock-solid
First magenta set-up, pretty decent (don't look at the corners, they're of no concern yet):
Center of the screen, again, not bad at all:
Then I switch to the white crosshatch:
Center of the screen, you can already see the difference starting at the top....
Top of the screen, the green is ABOVE the magenta....:
Bottom of the screen, the green is BELOW the magenta.....:
Resulting in this....:
By the way, these pics clearly show the difference between WG (low res) and Amplifone (mid-res) tubes.....