I have pleasant memories of the old Scientific kits too. But I also have some not-so-pleasant ones.
The big problem is that some of the kits had nice, basswood hulls and some had balsa ones. When I was a little kid my mother bought me a Scientific Flying Cloud. Not only the hull but all the other wood pieces (other than the round spars, which were birch) were made of balsa. As I imagine everybody in this Forum knows, balsa wood is just about the worst conceivable material for ship modeling. The kit was a box full of hopeless trash.