A few months back I ran across an undecorated Atlas refer shell at a local hobby shop. I picked it up for next to nothing with the intention of using it as a conversion to a Proto:48 piece. The photos below show the progress up to the primer stage. My usual caveat applies: I take a LOT of modelers license on these projects. This car represents a re-build if you will...AB Brakes and modern brake wheel etc. No specific prototype but this should turn out just fine.
I Started by removing the doors....this was painful as they actually work! ....but...they are out of scale. The roof hatches are similar in that they also work but the hinges are out of scale. I have not yet decided to replace the hatch hinges....
I scratch / parts built a new under frame using styrene shapes, Shapeways O-scale 3-D printed brake components, Tichy and Archer rivets and a few Protocraft items (couplers, draft gear etc).
I added brass ladders, correct scale door mechanism and a modern type brake wheel and hardware from Protocraft. The correct scale size hinges are Precision Scale pieces. Correct car siding was used for new doors and woodgrain was added. I filled the oversized grab-iron holes, re-drilled them and added .020 grab irons. I scratch built a brake platform, used the original valve and piping and formed new coupler lift bars again from .020 brass.
The ladders are press fit into holes in the sides and ends. Once painting is complete on the ends and roof the ladders will be popped off and the ends masked and the sides painted. The holes for the ladders are drilled through the shell so when they are re-mounted they can be permanently attached using a dot of gap-filling super glue to the through holes on the inside of the shell. It is a bit of an exercise but it works well!!!
The photo set below shows progress to date. Paint, lettering and Protocraft P:48 trucks and top pin couplers will be added to finish. More as I make progress......