Welcome to the forum.
Good sources you probably use already are E-bay and Gunbroker. Set up a search for "smith wesson parts". Some listings are kits of used parts that are usually from guns destroyed by law enforcement with some to all of the parts except the frame included in the kits. You can generally win the entire parts kit for the price of the part that you want if you had bought it new.
Post an adv on this forum under the classified section.
GUN GARAGE on Ebay (for screws)
George Dye (at David Carroll's) for old Smith parts, sight blades, etc.
Brownells: Gunsmithing supplies, equipment, gun parts, technical advice.
Mail Address: 200 South Front Street, Montezuma, IA 50171
Web Site: World's Largest Supplier of Firearm Accessories, Gun Parts and Gunsmithing Tools - BROWNELLS
Dave Bennett: Parts and guns from 1900 up to 1970's.
Web Site: www.22ammobox.com
David Clements - Clements Custom Guns
2766 Mt. Zion Rd.
Woodlawn, VA 24381
Clements Custom Guns
Jack First: Large selection of Pre- and Post-WWII parts. Sells working
parts to FFL dealers only.
Gun Parts Corp: Successor to Numrich Arms; many guns parts.
226 Williams Lane, West Hurley, NY 12491
Web Site: Firearm Parts & Accessories | Military Surplus | Numrich Gun Parts
Jim Horvath: Many parts for all S&W's (large and small) from 1860 up;
can reproduce parts.
Jeff Lee: Lee's Gun Parts (an extensive supply of gun parts, including S&W; Open to the public on Tuesdays, Wednesdays and Thursdays).
3401 W. Pioneer, Suite 2, Irving, TX 75061
Jan Matlega: Parts for Pre-WWII S&W hand-ejectors.
Mail Address: 528 Eddy Glover
New Britain, CT 06053
Poppert's Gun Parts: http://www.poppertsgunparts.com/
P.O. Box 413
Glenside, PA 19038
Tel: 215-887-2391 Fax: 215-887-5816
Charlie Pate: Provides screws (original & reproduction) for S&W Tip-ups and Top-breaks; author of books and articles on S&W guns.
Phil Saccacio: Phone: 540-456-6405
Dave Szilagy: Manufactures parts for older S&W's.
Mail Address: 3107 Electric, Lincoln Park, MI 48146
Mike Veilleux: Guns and Gun Parts
All Parts inc. for Pre- and Post-WWII S&W's.
Web Site: www.gunsnparts.com
Liberty Tree Collectors Phone:207-285-3111
139 Main Street, Corinth, ME 04427
Liberty tree collectors has original, CCH lanyard rings (but without the retaining pin) for $25.
S&W Parts; antique and new
Ph: 352 394-7412