PS -
1989Pre if this was me, here's what I'd do:
Get an alloy or stainless M6x1.0 thread bolt with a ~9mm shaft on it and a hex head OR see if you can find a "shallow head" hex bolt that's M6x1.0
If all you can find is standard hex head, take that M6x1.0 bolt ~9mm shaft with a standard hex head to a bench grinder and make the head "low profile". Note that alloy bolts can load up a grinding wheel if done excessively (one bolt head won't do it).