Thanks for the informative response, my estimate of year was obviously wrong as my memory from all those years ago is a little fuzzy now
But good to hear I'm wrong and the bike is better - lol. Although the info about the manufacture year being 90 could mean thats when I ordered it which is why I thought it was older.
I have just taken a measurement from the points you gave and it is 16 Inches so that helps clear that up too. I know what you mean about it looking even smaller, I think it must be the visual change in the "Triple Triangle" geometry from the larger bikes - I found a 22Inch frame on here and it looks nothing like mine even though they are identical, mine almost looks like a pseudo trials bike in comparison. If you put the bars down it makes it look even smaller.
I can only imagine that the info I got regarding the supply of the smaller bikes may have been a bit of "Spiel" by an enthusiastic sales youth to get me to take the available 18inch frame size by making it sound like the smaller ones were not available (Its fair to say I have become a synical 'ol man over the years - lol). I know they were very keen to sell me the shop stock bike but I had a Timberline of the same frame size and it fitted me like a glove so I was not about to buy a taller one and risk my future as a parent. Plus it meant I got to specify the Midnight Aurora paint scheeme.
Thanks again for the reply, it's really appreciated and quite nice to know a little more history about my trusty GT.