When did Cage replace Garcia in NRPS?

[JPollQs]

Does anyone know when Buddy Cage replaced Garcia on pedal steel in the New 
Riders? I know Jerry occasionally sat in on banjo or guitar as late as '73 and I 
think Buddy Cage was in place by late '71 or early '72, so I'm asking when 
was Jerry's last performance as a full time member of NRPS? Thanks for any help 
with this question,  Stu