Toni; I know little of FW Evans, except that one was up for sale a few years ago on Ebay.co.uk and someone in the UK won it. I tried to buy it, but the new owner wanted double of what he had paid a few days earlier, about $800. From what I remember on the auction page, the Evans builders were responsible for many innovations in the late twenties and early thirties, winning a few awards for there innovations, which I believe included the rear dropout adjusting screw.
Best regards, Peter
Peter W. Naiman River City Cycle Shop & Online Sales Assistant
Co-Chairman., Larz Anderson National Bicycle Show
Chairman., River City Midwest Bicycle Show & Swap
Member: Cream City Cycle Club., Milwaukee, WI
Coordinator of the Cream City Century
http://www.creamcitycycleclub.com/
5551 North Mohawk Avenue
Glendale, WI 53217-5034
Email: hetchinspete1@yahoo.com