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Once you are ready to begin looking at coaches in-person, there are any number of places to look. I found my first Overlander through a local "trader-type" magazine in a "blind advertisement". One thing that I have learned about these "local" advertising publications is that the accuracy of the description isn't always on-target my Overlander was advertised as 28' and the owner's didn't even know it had a model name until I pointed out the plaque beside the door.
One of the great resources if you decide that a Vintage coach is what you desire can be accessed via the link below - - there are many wonder ful Vintage units advertised at:
Vintage Airstream Club Classifieds
I found my Minuet through an advertisement placed there about two years ago. Only had to travel about 200 miles for just the coach that I had in mind and at a very reasonable price.
Just to give you an idea of fully loaded gross weights (when loaded for a three-week trip to the International Rally) - - the '64 Overlander (26' 8") weighs in at just a bit over 6,000 pounds while the '78 Minuet 6.0 Metre (19' 3") weighs in at just a bit over 3,100 pounds.
Your only problem with a Vintage coach is the desire for a Rear Bedroom. The vast majority of the larger 1960s and 1970s coaches will have a rear bathroom with center bedroom (24' and larger) - - the bedroom often has twin beds that can remain made-up as my Overlander has, but a pull-out double is another configuration (the pull-out double doesn't accommodate being left made-up as it blocks much of the center aisle to the bathroom when it is open). Starting in the mid 1970s, it was possible to get the largest coaches (27' and larger) with a rear bedroom, but the floorplan was still a less common alternative to the traditional rear bath. Rear bedrooms were not uncommon with the 1950s coaches, but often the trade-off was a less-complete bathroom (often without bathing facilities) in the smaller (under 24') trailers.
With the 1950s and 1960s coaches, it is not terribly uncommon to find one with a "custom" floorplan from the factory. Recently, two rear bedroom Overlanders have surfaced with these custom floorplans, and to add additional interest one of the coaches even had a second exterior door for the bedroom.