Hello, Bob..and Welcome!
Damage which is properly repaired is not a negative matter, IMO. ...as long as the Quality of the repair is as least as high as original-construction by Cessna. The best damage repair will be virtually undetectable except through the aircraft records. If the aircraft records
are not complete, especially regarding the repairs, then significant loss of value exists. There are very very very few 170s which have absolutely NO "damage history" … but there possibly exists many which have
un-recorded damage.
You ask for opinions on "value" and that is like asking for marriage advice regarding someone we don't know. (If we DID know her/him it would also be unlikely we'd post our opinions of them on-line.)
At any rate, the value is based entirely upon condition, maintenance records, location, flight and engine times (TSMOH) and installed equipment. Without your listing the details of such things (for example, you didn't mention the engine...is it worn out? New, Factory Remanufactured, Converted? etc etc) then there's no way possible to provide you with an opinion without visiting the site you mentioned, and not everyone visits that site or might not find the specific aircraft listing (you didn't provide a registration/serial number... even tho' I realize it's doubtful many A-models will be found there listed as "polished for sale at $42K). Nonetheless it's still difficult to evaluate an airplane when all one is likely to find there is the seller putting it's best foot forward.
Bottom line: You are going to have to inspect it personally or have it inspected by someone whose judgement you trust to place a value on it. Reading an advertisement will provide no more info for the reader than it does to yourself. (I once tried to help a friend buy a 170 in Georgia and called another friend who went to the airport and investigated it. The friend I called was a police officer and I therefore "assumed" he could investigate. He visited the airplane in the hangar, he talked to other pilots who knew the plane, he talked to the FBO who serviced it. He looked the airplane over and reported back, "It's a pretty airplane. Looks like new paint. Everyone says it's a great airplane."
I recommended to my purchasing-friend that we fly over to Georgia and give it a full inspection in-person.
It was
pure junk! It was bright red (I'm standing-by for my goofy fellow-members here to ridicule me on
that)
.... but it appeared to have been painted with
Sears Latex using a roller! The spark plugs were rusted into the cylinders so badly that it looked hazardous to attempt to even remove them! The radios had faces/legends which were unreadable and with corroded aluminum knobs. The interior had common household upholstery fabric. While the records appeared to be complete since manufacture.... they were "skimpy" at best and clearly avoided any mention of 50 years of useage/repairs. That trip was a complete waste of $1K of travel and hotel expenses, and I felt very embarrassed that I'd allowed...encouraged even.... my purchasing-friend to go look at it.
This airplane YOU are considering might very well be a great deal. There's no way, IMO, to evaluate it at such distance.
If you do consider it further, before purchase I'd recommend a full annual inspection as a pre-buy activity.
Hope this helps.
PS: I did find the advert. I'll say this: That looks to be an "odd" instrument panel from a 120/140 airplane and not what I'm familiar with as an "A" model. Look for records on that instrument panel re-design.
It appears to have a "lightweight starter" and an electric oil-sump heater installed. The engine time is relatively low, and could be a good sign depending upon recency and quality/reputation of the last repair/overhaul.
I'm not personally in favor of the 180/185 gear-leg mod on 170s that don't have larger/heavier engines but if you want to operate in the "bush" or off-airport it might have advantages. (Look for landing gear repair records in addition to that Pponk mod which I consider a plus.) The airplane likely has a history of such useage, so look for tailwheel bracket cracking on, and in the area of, that early-style small, steel tailwheel bracket. Hope this helps a bit.