Try Mcmaster-Carr for the nylon machine screws. Here is the online page:

http://www.mcmaster.com/#machine-screws/=ssz3ew

Ar 6.42 for a bag of 100 1" long 10-24 in black you could replace them every 3 months for several years if you are worried about UV.

Since you are up in Babylon you can use UPS instead of the usual fight to convince companies (Mcmaster is actually better than most) to use the USPS and that the USPS CAN deliver to a USPS Post Office Box.......

Now you guys have me all nervous about my Weiand tunnel ram.....