Start emailing & calling manufactures. Butter them up & request a patch. It's worked for me in the past. I recently took an old Dickies jacket sewd the patches on & made a neat little winter range jacket. Free advertising for them.
I appreciate the suggestions guys, but I'm looking for manufacturer logo patches (Glock, IMI, HK etc). Anyone have a source for those? I looked at all the sites linked, but none of them had any OEM patches.