Europa's used three different door designs: S1 (simple door window), early S2 (electric door window, button latch) and S2, TC & TCS (electric door window, handle latch, most common).
Interior light same as MGB and available cheap new.
Ash tray can be hard to find and expensive when you do.
Ebay has inexpensive alloy rads. See this thread:
http://www.lotuseuropa.org/LotusForum/index.php?topic=1451.0Tanks available from Steve on the yahoo list and from Lotus suppliers such as Dave Bean, RD Enterprises and Banks Engineering.
Windshield is available from Pilkington Classic USA.
Window seals and felts are available from Lotus suppliers such as Dave Bean, RD Enterprises and Banks Engineering. They fit and are not expensive.
807 engine help available on this forum and at the europa yahoo list. Parts are available, perhaps not readily, but they can be found. Just let us know what parts you are after and we can point you in the right direction.