Questionable keel bolts?

[Bfranz]

Recently had my 1977 CS27 surveyed and he says there seems to be some rust coming from the keel/hull joint and the bolts could be questionable.
It is an iron keel with what appear to be stainless bolts/studs. The nuts and studs show no corrosion in the bilge. There is no crack along the joint, everything looks nice and tight except for some surface rust on the keel itself.
1. do you think the keel needs to be dropped and studs inspected?
2. should I leave things the way they are and just pull out some of the caulking along the joint and reseal if possible?
3. Is there a chance that bolts were cast into the keel making them impossible to remove?

Thanks