If you search this site for "constellation" or "tag axle" you will get a few threads discussing similar coaches. Maybe one of those owners can be contacted or will chime in here...
As I understand it, coaches like my Tour Master 40 series were built in moderately small quantities each year (dozens, not hundreds...) so it is pretty hard to believe that thousands of tag coaches were made by GS over the years...but maybe they did.
On paper these look like very well featured coaches -- here is a representative 2000 model year brochure:
http://www.gulfstreamcoach.com/towab...r%20Master.pdf
Chuck