Last week I watched "Earth Vs. The Spider" a movie I haven't seen in a long time and lo and behold there was our own Wally and another 40 year old "teenager" including one of the guys you always see playing in Ricky's band (he was also in a band in this movie). Seems Wally played teenagers into his 40's. And there was Mr. Ziffel from Green Acres playing the museum guard who instead of running when the giant spider is coming after him decides it's the perfect time to make a phone call. The spider had a rather old meal. It was a fun movie though, almost like seeing Ozzie & Harriet Vs. The Spider!
https://www.moviemistakes.com/images/mistakegrabs/131900.jpg
http://www.thevideobeat.com/media/description-pix/earthVspider.jpg

A very interesting find. I looked up the movie and it was made in 1958– making Skip Young 28 at the time — and in his early mid 30s in the O & H eps — he ‘s mostly in 1960+ eps.
So yes it is odd for a thirty something guy to be playing a 20ish university student.