Dude you have to remember that these cars are usually purchased, then added onto. They wouldn't change the VIN at a limo factory, so the licensing office still thinks it's a standard sedan.
Good to hear our limousines are still well regarded in the US. If I can help with your queries please advise.
Lorne Stoddart, Jankel Armouring Limited, Weybridge, England email@example.com.
It would be interesting to compare your limo with my '76 Cadillac Fleetwood Seventy-Five Limousine (listed in this carsurvey site as a '75). It would be nice to take photos of both of them together!
Mine has a 151.5" wheelbase and is 252.2" long (just over 21 feet). 500-cu.-in engine. A big, heavy (6,040 lbs) and smooth-riding limo! Has two (front/rear) climate control systems, rear jump seats/footrests, power glass partition window and rear compartment radio controls.
I cannot comment about the Jankel, but I have owned both a 1962 Rolls-Royce Silver Cloud II and a 1972 Fleetwood 75 Sedan. The Fleetwood was very comfortable, but not in the same league as the Rolls. I have difficulty describing it, but the Rolls seemed to "command" the road (and the driver) whereas the Caddy just dealt with it. Being an American, I am used to driving cars the way I want. The SC resisted that. It instructed ME how to drive it (and I'm better for it). Also, believe this or not, the Rolls was WAY quieter at speed. I had it up to 100 mph and could hold a normal conversation. The Cadillac started to have some wind noise at about 80. Yes, I knew I was breaking the law, but the statute of limitations has run out.
I have taken my '76 Cadillac Limo up to 95 mph. and didn't notice any disturbing wind noise. Maybe a rubber seal or something on your '72 was cracked, broken or missing. At 95 mph, my limo felt like it was going only 70 mph and was quiet even at that speed. The extremely long wheelbase and heavy weight allowed it to float down the road!