GOOD NEWS!! The fastener place I go through found the source again. This is what they have:
3/8”-24 X 1 1/4” long slotted oval head machine screw, plain finish, case hardened. These are WWII surplus. I think they are the same ones I found several years ago. If, so they may have the raised letters on the head. See photo.
original on far right
I’m requesting samples again to make sure. Should have them by end of week. The price brake down is as follows:
Quantity of 500 $166.67 at $0.34 each
Quantity of 1000 $233.33 at $0.24 each
I’m also requesting a price for the hole lot.
What I need from you is a shipping address to get these to you if interested. My email address is firstname.lastname@example.org