Take the bashguard screws in question to a hardware store or home center and compare the size and threading to what they have in stock or to a display for determining that. They probably won't have the style you will want but at least you'll know the size.

Pictures of you crankset would be helpful, too. I had a super maxy on a bike years ago but can't remember the details. Bashguard fixing screws can be less standard than chainring bolt sets.

standard double chainring bolt set should fit. (Not triple - that would be for all three rings on the same bolts.