Holga Screws for Mounting Lens

Hello folks, first post ever on this web site. Thanks to the many hamsters running on their toy wheels which are used to power the web servers for photo.net. I had problems with the shutter not firing on my Holga 120 GFN. I removed the 2 screws which hold the shutter/lens assembly on the camera but stripped the head of one of the screws when reassembling the camera. Anyone have any idea which size I am looking for in case I head out to my favorite hardware store to look for them?

Thank you,