The 1995 yellow Kosmos logo Catan box is often referred to as the first edition of Catan. It was the box on much of the early advertising and at Spiel in late 1995.
I have had an example of the replacement card boxes for each edition of Catan for a long time. They are not rare and have been available for Base since 2002, and for C&K and T&B since 2007.