Are these still in use?
I believe the BCIT/BCOL single doors are long gone (I have a shot of one renumbered UNPX, and I've got lots of shots of similar cars with YARR reporting marks, which are probably the former BCOL cars).
The ONT cars are all definitely still in service, as are most of the CNIS and GTW cars. The CP (originally CPI) cars are still around, and I've shot one or two QC cars in the last few years too, even though a majority of the QC marked cars went to QGRY.
There's a couple design variations, and TLT is apparently planning on doing at least two distinct versions:
A later (1980s-90s, pictured on the website) version with 10 end ribs, 10' doors and no corner posts. (CNIS, ONT)
An earlier (late 1970s) version with 9 end ribs, 9' doors and corner posts (CP/CPI, QC, ONT)