Three good suppliers of screws, traditional flat head brass screws,
cut threads:

Lee Valley
fx 1-800-668-1807
P.O. Box 6295 Stn J
Ottawa, Ontario K2A 1T4
http://www.leevalley.com/

Woodcraft
560 Airport Industrial Park
P.O. Box 1686
Parkersburg, WV 26102
http://www.woodcraft.com/
tel.: 1-800-225-1153

Tacoma Screw Products
607 S. Fidalgo
Seattle, WA  98108
tel.: 206-767-3750
fax:  206-762-1632

Good luck!

Herbert Huestis
Point Roberts, WA