Somebody posted photos of a vintage North Face tent not so long ago and that tent may have had a tunnel entrance as well. Quite common in the day.

Penny, I find it interesting that you did repair work on Scott Tents since the items are so obscure, certainly in the US. I think Scott Tents are really cool, but I can't imagine actually using one, certainly not if I had to transport the tent. Given the conditions the tent is designed for, they must weigh a ton or two.