Main spring for a 18 sz 23 jewel Special Railway

Does anybody know where I can get one

Marv,
I can only find one number listed for the 18 size Hampden...#1696...If you can't locate a Hampden spring a 18 size Illinois (Model 1-6) spring would interchange...Also a 18 size Rockford spring will interchange with your Hampden...Measurements are 20 x 2 or 3 x 21 1/2...Maybe someone else will chime in if I am not right on this...

Thanks for the info Gary. I have a donor Hampden 18 sz. When I removed the barrel out of the Special Railway I found it came apart at field repair. Some one in the past cut the ends off a broken spring and soldered them on a different spring. It is real interesting to look at. If I get a chance I will post a photo.