Here's a later version of Glen doing Wichita Lineman with Stone Temple Pilots. At least in this version he's playing both the intro and the solo with a Danelectro Longhorn Baritone guitar with a 29.72 scale length which is shorter than both a regular bass that's 34" scale length and even a short scale bass that has a 30" scale length, but longer than a standard guitar that is usually between 24 3/4" on a Les Paul and 25.5" on a Strat.
Glen Campbell - Wichita Lineman with STP
Here's some specs on that Danelectro Longhorn baritone
Wow….how did I not know this existed! Love the song and the DeLeo brothers. Thanks for sharing this!