In my opinion, these are the very best pinball links on the web...

Mike Saunders' Indiana Jones Page
Everything you ever wanted to know about but couldn't find it here.

Ed Cheung's Indiana Jones Shop Out Page
Extremely detailed account of a complete overhaul and lots more useful stuff.

Jay's Jackpot Lights Mod.
How to make the display panel jackpot lights work like the ones on the prototype pinballs