Could someone please verify the size, I just checked mine and they are 10-32 it appears.
I got some allens from the hardware store, but the head was too big around, so you can chuck them in a lathe (or drill press) and hold a file and reduce the diameter-if you don't know what I'm describing, don't try it, also use information at your own risk. Use touch up blue if black, polish if stainless.
JW