Marcos Maniacs

Does anyone know the source of the dome light between the seats on 
Marcos cars?  It has a clear magnifier in the middle and some type of 
bezel.  What did this come out of, or is there a good replacement?  
Also, anyone have the Ford V6 2.8L in their car?  This engine has the 
distributor in the back.  I'm curious if anyone has had luck with any 
modifications to this engine and what they are doing for cooling 
(radiators). 
                 Thanks, Steve V. in Arizona USA