Hafler dh200 mono amps

I've got three dh200's, one two channel which I built in the early 80's and still powers my 15" jbl 2235 subs, the other two I set up in mono to power a pair of DQ-10's, they worked very well but, they've been in boxes (Haflers) for probably 15 years. I dug them out today and powered them up, the one works but has a .15 vdc offset but quiet. The other one blew the 5 amp power fuse right off but ran OK after replacing it, only problem, is it has a low level hiss and all of the mosfets warm up pretty quickly. After this long, I'm sure all of the caps need to go & probably a lot more that I've not paid attention to over the years, the last thing I remember doing to improve things was putting in poly props in the input stage. My question is a couple fold, one, how can one adjust the dc offset and two, who is the Hero on working on these things in the midwest? I'd really like to get these back up and running, but I don't have the time to do it myself (momentary dip into reality)
Thanks
GB