My guess would be that it was only made within one or two years on either side of the 1978 date, since it's not in my 1976 or 1981 catalogs or in what's probably just a partial 1979 catalog (the ones from the 70s are really just small folding booklets, "catalog" is too grand a name for them.)
By the 1983 catalog page I've shown below, that style had been "upgraded" to the two Shoulder Pouches, the larger one of which became the Station Bag.
Almost all the vintage bags had a 2-piece hangtag made of two halves glued together. It's not a problem, our rehabbers at the Rehab and Rescue thread usually just glue them back together again.
OOHHH I want one of these, the smaller ones!
I don't think I've seen one on ebay, are they pretty scarce?
I think I've seen one a year or two ago.