It will work for the spinner bolt, but a 10-32 is about .006 smaller and will strip out if you use one in a place designed for a 5mm, like the prop bolts...
I gotta ask Dave why an engine made in Arizona, USA, uses metric bolts...
Yes, some of the parts are made elsewhere..The crankcases are made from 7075 aluminum in Tucson, AZ...To the best of my knowledge the ONLY model airplane engine cases made on a CNC machine from 7075, the best and most expensive aluminum alloy, not from CHEAP POROUS castings like some other engines...
NO, not all engine cases are CHEAP and POROUS...