Actually 4 stainless steel bolts with a combined cross sectional area of 200sqmm . The bolts are still required to bolt the 25 thick base to the base plate. The cross sectional area of the cast aluminium mount base is about 1000sqmm. Perhaps a poor idea to call it a rat cage. More a bee slot.
Still no idea of maximum tension required.
According to some rules of thumb an alloy thread should be 3x diameter , so for the 10mm bolt , 30mm which is about what is available and can take 1500 mpa or 90kn.That should exceed the strength of the mild steel or 316 bolt which yields at 250 mpa or 9.8 kn for M10. Sound right?
Better buy a better bolt with the full 30mm or so engagement.
http://tribology-abc.com/calculators/default.htm