Like the last few examples, this comes from a collection whose original owner was involved in aviation in the 40s. I wonder why he was here. A vacation, perhaps. It's from the days before Route 66 had slipped into mythical status, I think - it suggests that road's famous but still in use. The Tewa is still around as of 04/06, it would seem - but the web is often slow to catch up to these things.