I bought 5 of the Jackson sharp open air cars(not knowing they'd produce another version later on) and I haven't had the foggiest idea on what to do with em...until yesterday.
B&O Switcher pushing the cars into the shops
So far so good
About to enter the paint booth, thinking about fully enclosing them with window glazing instead of leaving em open as originally planned.
http://www.nps.gov/muwo/learn/historyculture/upload/MtTamMUWOrrIDP.pdf
https://www.google.com/#q=mt+tamalpais+gravity+cars&imgrc=9yhNZ71Eqt6s1M%3A
https://en.m.wikipedia.org/wiki/Mount_Tamalpais_and_Muir_Woods_Railway
This page has a video of the actual gravity car ride, albeit in the roofless cars that were also used.
http://foundsf.org/index.php?title=Muir_Woods_by_Gravity_Car
the 4 that i've done(i'm saving the 5th to for a before and after shot, then that will be modified) will be assigned to Strasburg RR. I have 4(out of 6) that were factory made for Strasburg itself. I also have a baggage and 2 combines being painted up for Strasburg. I also did an engine.
You can see the engine and one of the cars here.
I did something simular to that with a Athearn Obs. I made 1/4-1/3 open (Obs deck end) and the rest was enclosed.
If I may ask, what material did you use for the sides? I might be interested in doing this as I've been looking for mid size passenger cars to use, but didn't want to use "old time" cars.
Styrene, I used the Evergreen stuff. I did two 2-plank sections, and a 1 plank section.
I'm currently on break from model railroading however, these cars got to me a bit as I can't seem to finish painting them. evertime I think "Finally i can decal soon" i find something i missed, or the paint comes off when i peal off the masking tape.