My 1971 C26 MK II has severe rust/corrosion on the exposed part of all 9 keel studs, to the point where there is not much of the nut/washer left. Any advice or lessons learned from fixing this issue would be appreciated. The boat yard suggests shearing off what's left of the nuts & studs and dropping the keel and remounting with new hardware.
Has anyone tried to back the studs out one at a time, maybe using a smaller diameter reverse threaded bolt?

When on land take out one threaded stud at a time and replace it with a
stainless steel hexhead bolt with large washer. This has worked for more than five years on my 1970 MKII.

For anyone curious, was able to clear away the corroded nuts/washers/mounting plates (a power grinder is a wonderful thing). Thankfully, the studs were solid and threads sound.

I drilled 5 new holes in which I tapped and thredded new bolts along with s steel plates and it seems to be working fine. I didn't have to drop the keel. I you do drop your keel would you be so kind as to take some pics and email them to me. Thanks.