I don't know about the Catalina
27, but there is a debate amongst boat designers as to what the best keel
bolt material is.
Some go with steel
since it is immune to crevice corrosion
, but will result in a general rusting. Others use stainless to prevent the rust, but accept crevice corrosion
. The real problem is both these materials are terrible in this application.
Frankly I would require the current
owner to drop the keel
and inspect the bolts. It is a pretty easy operation, but it does require a travel lift
or crane. Once done though you know what you have.
As for the 'fixes' they are all suspect in my eyes. Lag bolts, anchors, and the rest can't be considered reasonable alternatives to a cast in place threaded rod.