There are bits to be salvaged from Ruhl (1989), perhaps, but it might be easier to start elsewhere entirely.
I fully acknowledge there is certainly an appeal for monosemy as a theoretical construct. The ability to schematize all usages or senses within a single abstract sense does indeed simplified and elegant semantic theory. Such a theory is an attractive prospect for all linguists.
Generative grammar has moved on from its old theories about syntax. Can we please do the same with their semantic theories, too?
We’re getting over the peak and headed toward the end. The practical take away is coming.
Semantic theory: it’ll get harder before it gets hardest.
Meaning is hard. Unfortunately, I’m not going to make any easier here.