I don't think I ever knew about the FuturLiner until my wife and I were at Disney World FL for our honeymoon in November of 1994. GM had a big part of something going on at DW at the time. IIRC the FuturLiner's Parade of Progress was shown in a video at DW's Carousel of Progress. I'm pretty sure the cars in the "Test Drive" ride (not sure of the name) were supposed to look like something from GM, maybe a topless Saturn. I definitely remember at least two "second generation" Saturns (to be released in 1996) sitting in the concourse on the way out of one of those two places.
As for the picture I posted earlier, the top of the door and quarter panel being so flat is what threw me off and caused the picture and my traipsing around the internet.
What I believe it was and why (not just because it was on the internet):
The large well known 1957 side trim does away with it being a 150.
The top of the doors and quarter panels being so flat on top removes Bel Air from the possibilities so we're looking at a 210.
The top of the doors and quarter panels being so parallel to the bottom edge removes everything but the Handyman Station Wagon and the Sedan Delivery, both of which were two door cars with the long station wagon roof.
Why I'm not sure about which one it is:
All Handyman Station Wagons had side windows but the Sedan Delivery only had side windows as an option and there's no clue as to what this one came with new.
I couldn't find definite info regarding the lower rocker trim.
Another reason I'm not sure and I wish I had a picture from the rear:
The Handyman Station Wagon had the rear clamshell like the other station wagons.
View attachment 305751
The Sedan Delivery had a large one piece liftgate.
View attachment 305752
After all that I'd say the other modifications were the Bel Air spinner hubcaps and the chrome trim on the quarter panels that is longer than these pictures show.