RE: head bolts for OS Max .35
Dwreefs,
Don't bother ordering these bolts from a hobby supplier...
Just take the engine to the nearest technical supply shop and go to where fasteners are sold.
You will easily find the metric bolt size, with any head (flat, Phillips, or hex socket) and they will only cost you 'a dime a dozen'.
I am sure Alberta Canada has enough metric fasteners available. You will find new ones for the back-plate also and a stronger prop-nut.