Here are a few representative photos of my Clark Benson aluminum cars that I purchased in the late '80s or thereabouts. Basically, these are scale length (~21" except for the baggage car which is ~18"), LIONEL extrusions, using LIONEL car ends, but with a Masonite (?) "frame" and clear film "window" inserts--no trucks or couplers supplied.
First, a photo of the basic extrusion:
This is one of three vista domes with the cast lead dome frame:
This is the "collection" in their original boxes and handwritten labels (by Clark himself?):
As I said, I'll start a thread showing these Clark Benson cars in more detail, including direct comparisons to LIONEL's PW "wide channel" aluminum cars.
In the meantime, thanks to Scott, S. Islander, and Bob2 for the info and photos.