One of the ones on the face?
You might have some luck if you ask all the dealers, but for such a small item it may not be worth their while, even if you order, say, 4 as spares.
Also, I would imagine that there might be different screw thread sizes in the different models - I know that the strap lug screws seem to differ between different models available, and none seem to be the gen 1.3mm hex head...
Hope you can find something!