Allen - The album title is "Handyland USA", and his playing is not too bad - basically one chorus per tune - everybody is a little tired, including Davey (the recording session finished at 6:30 a.m.).
Then again he plays well on the Gerry Mulligan Songbook, both on tenor and a very dark toned alto (probably the highlight of the disc) - and that was 1957!
Anyway it wasn't age I was referring to - he did some his greatest playing with Fats in the late 40's, and qualitively, that was hardly "boyish" ...
Q