Hello,
On my Iron Maiden Premium, NIB, I have an issue with the sarcophagus lock.
The first time I light the MUMMY letters, the ramp diverter opens and I can send a ball into the sarcophagus. The screen animation for the first lock is displayed.
Then, the sarcophagus goes completely down and release the ball into the "underworld" scoop, which eject it. The ball is not kept into the sarcophagus
At this stage, the MUMMY letters remain lighted (solid) and the ramp diverter opened. If the ball takes the ramp, it goes again into the sarcophagus, then to the scoop.
I tested the switches : they all work well, however the #40 detection time is very short. I don't know if it should last longer.
I tested the motors also : they all work perfectly. However, for the sarcophagus, the positions 64 and 65 are not corresponding to any phase I saw during my games.

Thanks ! I took your idea and I noticed that the ball was not pressing properly the switch, as if it was not enough heavy. By just adjusting a bit the switch with a clamp in the sarcophagus, it seems to work know. Sometimes, in multiplayer, the sarcophagus seems to "forget" that he has a ball in, and he is looking for it... But maybe by making additional adjustments...
Otherwise, I like your idea of replacement; but the link seems not good though.