I have bent the metal shielding upwards enough so that it can't come into contact with the board. The PSU is a standard weak A1200, which should manage the 1230 board since I have a Flash HD instead of a mechanical one, and no external drives or other peripherals that draw power. The LED does not change brightness, it glows steadily with it's regular strength. The RAM module looks ok, no signs of damage or a bad fit.
For a start, take the upper shield and throw it in the nearest bin......there, feel better now?
Secondly, if fitting the 'trap door' exerts any kind of pressure on your card, then don't use the trap door.
This kind of approach works better for keeping your card where it should be:

And although mucking about is part of the 'fun' of classic hardware, I personally wouldn't be too happy if I'd brought a card that doesn't actually fit.