Had a look at Lee Valley and ordered a few bags of the smaller sizes. Should be just the thing for all those missing screws on my Speed Graphic. Thanks for that tip.
The only trouble was with their International Address form. They had 3 fields: Street, City and Country. No State/Province and no postal code. Very, very strange since postal code is an absolute requirement for most western countries. Just added it all to "special instructions" and hoped that it would be OK.