Chuck, it sounds like the Caliber uses a stronger (and less conventional) chainplate fitting. In conventional fittings, 4200 would be the wrong material to use because it is not designed as a highly flexible seal, nor is it easy to dig out and rebed every year or two. It's overkill (too strong) for that job.
For your Caliber, it might be right--but since there's no need for that much "grip" and a six-foot prybar is inconvenient...it probably is still the wrong goo for the job.
I think it was a Westerly where I saw the chainplate deck connections mafe up rather differently. Metal plate with a D ring, one above deck, one below, sandwiched together with four bolts. Sounds like what you have--and it was designed for the North Sea, to keep water out of the boat. Still, those bolts MIGHT work, MIGHT leak, so something that is very stretchy, very conformable, but removed and replaced without the six-foot prybar might be the better choice of sealants.<G>