Personally I don't think the 2+2 is the ugly cousin, it is all a matter of opinion really, the number of sales of the 260Z 2+2 in 76 & 77 speak for itself, compared to the 2 seater coupe! The 2+2 in numbers today have now in my opinion diminished very quickly but the cars were generally better looked after from a history point of view because of the type of buyer back in the mid 70's that could afford one. I have posted a photo of my 260z coupe in 75' but I have no idea where it is, even if it is still alive!! Your comments about my difficulty of buying a genuine manual zed based on the time it took me to buy is similar right now today. I have a stock standard Nissan 200sx S15 R-spec the same age as my 260Z when I sold it, 9 years later it is still immaculate and an unblemished vehicle but look at what you see on the roads mostly heavily modified cars many with panel damaged and only a few running around left stock standard. The zeds I looked at during the 80's were already rust infected, carpets torn up from heater leaks, duco heavily oxidised, seats ripped and dashboards cracked, mags without centre caps, consoles cracked, still a bit the same today really but the coupe I sold was mine from new and still like new I just didn't know how badly other cars had deteriorated when I sold it.
The other thing about the coupe is it was introduced after the Datsun 2000 sports and progressively put out of business the MGB, Jensen Healey, Triumph GT6 and TR6, Alpha Romeo Spider which were considered sports cars because of the thoroughbred 2 seater rag top being referred to as a real sports car, 240/260z were called tin tops not real sports cars until their racing debut helped them over the line to join the list of "sport cars" as with Porsche, Mustangs etc; Lynton 
Sorry I didn't mean to tarnish the 260Z 2+2 with the ugly stick.
I suppose I just interpreted your comment "Oh it is really good to see some genuine 2+2 interest on this forum." in this way.
Yes beauty is in the eye of the beholder and this beholder loves the 260Z 2+2 shape !!
RE: the 7 years it took for you to find your one owner 260Z 2+2 in the 80's indicating how hard it was to find an original unmolested 260Z 2+2.
The 200SX R spec comparo is a great comparo to when you were searching in the 80's for your 260Z 2+2 if a person was searching today for a one owner 200SX R spec as indeed your description of modifying is accurate.
The 260Z 2+2 was not considered classic in the 80's and thus not respected to keep original likewise the 200SX.
If searching for an original 260Z 2+2 today I think if any have survived I'd expect (hope) that they wouldn't be modded like they would have been in the 80's/90's....... but then it's not unheard of that people mod original cars
Other things that are different when searching for a 260Z 2+2 today when compared to the 80's, is that today there is the internet. This really has opened the search parameters up big time for buyers.
You get to view and read about allot more cars than just having the local rag, newspaper, word of mouth or monthly "Trading Post".
In saying all this I do agree that the odds are against me of finding the car you found in '89 - that is an original owner 260Z 2+2 5sp but if I do I'll be buying it immediately as I'm sure it'd been babied and cherished by its loving owner for them to have kept it all these years.
Nice commentry on the "tin tops" too
Your 1975 260Z 2+2 was a lovely car. Very nostalgic photo's.
Did you ever use the luggage rack?
Was that a factory option fitted by the dealer?
I would have thought it would have been a added risk for rust with the drilled mounting holes?
