Help me identify these late 80s pickups

[Evol]

Hi everyone, they proposed these pickups from 1989. They say they were on a custom order Les Paul from 1989. The curious thing for me are the slotted brass screws at the base. They come out at 7.85k neck and 8.06k bridge. Could they be the prototypes of the '57 classics in your opinion? Or what else?

 

[Hackubus]

The GUSA stamped baseplates say 490/49X series to me. But I’ve never seen cream 490s before that I recall.

 

[Gibbons59]

R-4 and L-8?