Probably way too late, but they're #6 x 1/2" oval head black oxide Phillips on my 98 verb
here's a link to the mesa ones for sale at a $1 a piece
https://store.mesaboogie.com/products/screw-6-x-1-2-phillips-oval-head-sm-black-oxide-logo-grille-screw.html
or you can get 100 for $6.85 at...
