Mach E,
Your post is the one that makes sense....
The 50 year old airframe. Total time is important and heavens knows what time has possibly not being logged by previous owners. Importantly though, this class of aircraft does not require a really accurate count of landing 'cycles' Islanders were made for short haul work and a ratio of 3 to 6 landings per flight hour might not be uncommon. Certainly common in PNG, Indonesia, small Air taxi's operating around the luxury Island resorts.
Need to have a close look at the structure!