Oh, and rear brake cable goes through the top tube too...

The same basic bike may have been in the catalog for a few years. I don't know for sure if mine is actually a 1971, but I know the original owner graduated high school in 1974 and she had it for a couple of years before that.

I suspect mine might be a year or two newer than the one you saw based on Simplex vs Shimano, but I could be guessing in the wrong direction... or maybe it depended on the specific run.

EDIT: I just looked again and noticed that the bike there didn't have the brake cable internally routed... I guess that mine could be a 1972 or 1973 model.