All:
Thanks for your advice. I've checked with the local LDS. He agreed that the exterior appearance of the rig appears to jive with the "only used for 4 dives" story. He quoted $132 for a complete overhaul of the first, second and octo - which I agreed to (before you jump on me - prices in Alaska are higher for everything). He said he will test the hoses and if there are any problems, he will replace them with used shop hoses for no extra charge. I dunno how used "used" is, but I know he's not going to give me something crappy.
I'm going put the octo on my existing regulator set, replacing the Air2. That will leave me with the first & second as a backup rig of sorts, or for use with a future pony bottle. He confirmed that it would make a great pony rig. I elected to get the Octo serviced NOW so I can put it on my existing regulator, and not get the first & second serviced until I get the pony bottle, probably in the next 6 months or so.
By the way....about the comment of maybe using this rig for my wife....no, I don't think she deserves inferior equipment. However, fact is, I have a rig already, she does not. I also dive a lot more than she does (she isn't really into the cold water stuff), and she is probably only going to go diving when we are out traveling somewhere. I figure bringing her a known good reg set from home is likely to be more reliable than something from an unknown rental fleet. Anyway, that's why I was considering this rig as something for her to use, not because I want to give her crappy stuff. If I thought there were anything crappy about it, I wouldn't let her use it.