How much difference is there between the mounting holes of 501 vs 511? Just wondering if I were to upgrade from 501 to 511, would the body fit without modifications to the mounting holes? Needing to cut something a bit more than for 501 is not that big of a problem, but if the mounting holes don't line up and they need to be enlarged to an extent that there is a visible hole on the body when fitted etc, the result is just plain ugly
