The inverter has nothing to do with the tunneling, only the backlight. The good news is swapping Active/Passive Color/B&W screens are a cinch to do.
Just swap screen and you would be good to go, don't even need to swap the Mobo.
I did that with mine, and right now I am having an issue with my screens where the lower-half of the screen has alternating Color lines (like one pixels from halfway going down of each: red, green, blue, yellow, white, repeat)
Not sure what causes it, but it's probably the display controller. Doesn't do it on my Black and White Passive-Matrix LCD.
Btw, there is a seller selling the 33Mhz PB 540 Daughter cards on ebay ATM. I just bought one and it cost me $3.59USD shipped. Should be here within the next two weeks.