Screw size for '84 Spectrum LX Backplate

Many years ago I inexplicably removed the backplate from my Spectrum LX and have since lost it and the screws. I have a replacement plate but no screws. I hesitate to try generic screws like you find on Amazon because I don't want to damage the holes with the wrong size or thread. Does anyone have the dimensions of the screws? Thank you.

Take one of the pickup ring screws out and see if that fits?? Or one of the pickup selector cover screws....

Thanks! Looks like the pu ring is .5 inches and the selector cover is 3/8 inches. The .5 incher seems to be right. Any advice on a compatible backplate? The holes in the generic Fender replacement I bought don't not quite line up.

Somewhere in here is a drawing with dimensions of a Spectrum backplate; make your own! 

http://www.westoneguitars.net/fixme/restorations-modifications/spectrum-tremolo-spring-cover-dimensions/

You can buy the plastic from Stewmac, or your local plastic supplier!, or use a DVD box as a donor...