Missing Mystery Chassis screw - Help!

[Addictedtokaos]

I just noticed Im missing the "Chassis Screw" on my used Rectoverb Combo.

Its obviously a machine screw, Can anyone give me any more info on it so I can find a replacement.

Length?
size?

 

[fluff191]

Contacting Mesa will be your best bet. They can send one out to you.