After a long search for the safety spring on a NID, 1932 Ithaca double,I have amassed a fairly good list of gun parts dealers who have old shotgun parts.
There was a poster looking for a safety spring for a FOX, Brownells and Midway carry kits with several springs each in them kinda pricey though)
Jack First Inc ( This is where I found the spring)
1201 Turbine Drive
Rapid City, South Dakota, 57703
605 343 9544
Galazane@msn.com ( these folks specialize in restoring Fox Stergworth shotguns. They may or may not sell parts)
Empire Gun Parts
570-275-5487
empiregunshop@yahoo.com
Diamond Gun Shop
diamondgunsmithing.com ( Ithaca Parts)
Conneticutgunshop.com
860-225-6581
Sharps Gun Shop
RR4 Dunville
Ontario, Canada 1A2WC
905-774-6368
Gunworks of CNY
315-363-7041
cnygunworks@hotmail.com
Popperts
PO Box 413
Glendale, PA 19038
215-887-2391
www.poppertsgunhparts.com