I tried all the local hardware stores and could not find the screws I wanted, so I ordered them mail order with their big minimum quantities. I am keeping the ones I need and selling the rest.
For guide and finder scopes.
Black Nylon Knurled Head Thumb Screws:
1/4-20 Threads by 1-1/4" long.
10/32 Threads by 1" long.
Set of six for $4.
For set screws and other.
Black Plastic Knurled Head Thumb Screws with Stainless Steel Threads:
10/32 Threads by 1/2" long.
Set of three for $6.
Note: the 1/4-20 Stainless Steel Threads by 1/2" long are all gone.
Add $2 for shipping.