Fillister is the name of the screw type, Phillips of you can find them. Specs: 10-32 x 5/8”. From what I’ve read here, this should be the same for all Wilton’s, or maybe at least the older ones.
They hard to find in stores. Order them online if you can. My inquiry on this is
in this thread or search “Fillister Wilton” and you should find more on this.
The problem with most other screw types is they are too wide, but you can turn them in a drill and shave them down with a file or sandpaper.