I recently inquired about the beer stein in International Street and was educated a bit. Is there record of what was created for Kings Island by him or other parks, venues which large scale would have been produced? Just throwing this out there....the puppet tree was probably years after and shipped in.

There's an excellent article on Coffey in the August 1977 issue of Cincinnati Magazine. It references a lot of the things he had created up until that point. The article starts on page 64.

https://books.google.com/books?id=jR0DAAAAMBAJ&lpg=PA64&ots=Jj22UkFj2t&dq=cincinnati magazine farrell coffey&pg=PA64#v=onepage&q&f=false

Regarding the puppet tree, that was created in 1982 and near-identical versions were added to other parks around the same time (including California's Great America and Wonderland Sydney). I don't know how long Coffey stayed with Kings Island and his involvement in other parks, but a lot of the 1980s Hanna-Barbera pieces were duplicated across the chain (like the Hanna-Barbera Carousel figures). It's possible Coffey could have worked on it... hopefully someone else knows more and can share.