A Beetle is a Beetle is a Beetle . . . right? Like David said, looking at the cars in the brochure gives enough details to narrow it WAY down. Without looking anything up and not being an expert on old Beetles, I can narrow it down to a three year block of time pretty easily. It's after the Oval Window era, so it's got to be 58 or later. The generator stand is part of the block, so it's earlier than a 40 horse which debuted in 1961. So, the Bugs featured in the brochure would be either '58, '59, or '60 models wouldn't they?
Other clues that may help narrow it down even more (if you know when these features started or ended):
the humped gas tank
the two spoke steering wheel
80 MPH top speed on the speedometer
the wiper arms
the tail lights
the turn signal switch
Solex 28 PCI carburetor
There's lots of other details to work with that should pretty much date it without it being dated. I'd bet if David "studied" on it in person, he could get it down to an exact model year . . . and tell us if it was early or late that year!
Regardless of when it was printed, it's a pretty cool brochure. Being that it was stamped by an early VW Salesman from Chattanooga makes it even cooler! Having someone on our message board who actually knew the guy . . . priceless!
