I happen to own a similar vintage 1206.
Perhaps this resource would be helpful for you, I suspect that I may have to perform this work on my 1206 one day.
Note--The 1206 does not have bleed-off resistors on the filter caps, I don't know about the 1205. If it does not, then you should manually bleed off the filter caps charge before working on the amp. A shock from one of those charged caps will not be pleasant!
Parasound Authorized Repairs
norbern.com