Sadly, Morse is afflicted with serious arthritis. Notice how he plays much more from the elbow, now. Rick Beato did an interview with him in which he goes into, among other things, his efforts to find workarounds.
I saw him just once with the Dregs at the Catalyst in Santa Cruz in the late 70’s. One thing I love about older players is their lack of ego and their focus upon playing for the music and playing to communicate emotion.