I measured the screws on my 4-switch Woody and Vader.
The short answer is you need four screws of size #6-20 (aka #6) in length of 5/8”. Details below…
Quantity 2 #6-20, ¾” length screws are at front.
Quantity 2 #6-20, ⅝” length screws are angled at rear. They are installed at an angle, parallel with the silver switches.
I think you could use ⅝” long screws for all four locations but factory used longer ones up front.
Measured sizes to help folks convert to metric…
Diameter 0.136 inches
19.7 threads-per-inch
Length: 0.725 inches and 0.600 inches