Interesting what the experience is on both sides of the pond. I first heard Silence Is Golden from the Four Seasons, probably shortly after the 1964 recording as the "B" side of "Rag Doll." And yeah, I heard Denise from Randy and the Rainbows* in about 1963. Never heard the Blondie recording until today.

At the Mudcat Singaround today, somebody sang "Pack Up Your Sorrows," which I learned from the 1966 Peter, Paul and Mary album. The song was written in 1964 by Richard Fariña and Pauline Marden (the third Baez sister). I didn't hear the Richard & Mimi recording until long after the PP&M recording became popular.

*Not to be confused with the delightfully clever https://www.randyrainbow.com/