If you do a topic search you will find an earlier discussion on using various production car and relatively contemporary side mirrors. Mr. Dangerus started this discussion a while back and it included photos and suggestions about adapting various currently available door mirrors to Esprits.
There were two mirrors installed on the G Esprits. One with an oval shaped stalk and the other with a scalloped stalk. Mine has the oval shape.
Just bought a right side off a Fairway London Taxi from the UK. (Bunch of them on Ebay used for cheap...It was $45ish shipped to Texas) They're electric, but you have to get a different gasket between the door and mirror stalk. (I'm still trying to source the gaskets Stateside) I haven't had time to check the electrical diagram to see if they're the same wiring wise.
The UK Ford Capri also has the same mirror, but its remote manual.
The usual Lotus parts places probably have them new as stated above.
There is a thread somewhere on here that has a lot of info too.
Hope that helps, Rob