Source for thumbscrews on McMillan stock?

[Toebuster]

Snapped the round head off one of the two thumbscrews that lock down height adjustable cheek piece on a McMillan stock. Checked their website, and a few others as well but no luck. Anyone have any other source until I call Macmillan on Monday?
Thanks.

 

[Trigger Monkey]

I've bought thumbscrews from McMaster Carr for my McMillans.