OK.
First, the good news (for US and Canada owners, anyway) is that fasteners threaded into A7/A10 aluminum components are INVARIABLY Whitworth, for which the direct substitution is UNC, a coarse thread available at your local Ace/TrueValue/local hardware store in socket head (Allen), hex head, Philips head, etc. Zinc plated, stainless, brass - you got it. So, don't go laying out good funds for overseas stuff. Calibrate a piece of coathanger wire to find the depths of the various holes, paying particular attention to "blind" holes.
"Bad" news: Fasteners threaded on and into the non-aluminum components have no substitute. The head bolts are BSF (3/8-20) and the rest are CEI (typically 26 tpi) plus a few BA screws in the electrical pieces. (One peculiar application, however, is the brake spindle (both) which can take a 7/16-20 UNF nut.)
If in doubt, use a thread pitch gage to determine the fasteners particular to the hole/spindle in question.