AAR M500 observation car.

[Sumpter250]

Thanks guys, yes that's the car. I didn't know Rivarossi made one (has made).
Where ever I look online, it's heavy weights , or some budd design cars, and this type of car doesn't seem to be in production by anyone at present, and it is @*$£ hard to find anywhere. Those brass models look great too! Koos

Yeah, I found a number inside the one car I have, and went to the Hornby ( owners of the old Rivarossi ) website, to see if it was available...not. Checked out my local hobby shop, they're out of stock there also. looks like "our" Swap Meet forum, or "Evil Bay" might be your best options. The coach I have, measures 85'-6" overall length, 83'-10 1/2" side length, 7'-9" side height to the edge of the roof, and 2' from the lower edge of the roof to the top. Trucks, center to center 60'. Truck wheelbase, 8'-9" center to center.
Hopefully, with those dimensions you might be able to determine any of the others. For example, knowing the side height, you could use a set of proportional dividers ( the pivot point is movable ), set so that the height of the side at "a point", will produce 7'-9" on a scale rule at the opposite end of the dividers, and you could get all the vertical measurements at that point. The horizontal measurements are a bit tricky, because they change in direct proportion to the change in vertical height in the photo.
Often, the vertical:horizontal ratio is most accurately determined from the "near end" in the photo, and could be compared to the truck wheelbase, for the horizontal distance at that location.
I used that method to scratchbuild several tri-level auto racks. When Walthers released their first kits, I was happy to see that their cars and mine were the same length and height. May fortune favor you.