Scew bottom screws

[Vintage AMT]

Looking for some replacement screws for AMT, can anyone tell me what the threads are called? I;ve looked at every type of thread chart and these do not show up.. Need about a dozen.

Thanks

Edited April 24, 2022 by Vintage AMT
spelling, or the lack of.

[TooOld]

U-Drive Screws . 

[espo]

I think you will find that these screws were unique to the application. As I recall the screws used by AMT and Jo-Han were also somewhat different from each other. The real fun ones were usually found on the early friction type cars with the metal plate for a chassis. They were attached with a one way screw. They were installed with a straight blade screw driver but the screw head didn't have any provision for the screw driver to remove the screw.