There are a lot more variations in these Canadian railway-marked 'hives than meet the eye. Here's a trio that might make a nice addition to your lineup. L-R:

1) green ink-stamped CNR. High quality, european-made porcelain. Possibly produced by Merklin in the former Czechoslovakia. This one has a small flake on the outer base edge and two large black hairline bruises on the base, and some scuffs on the crown. Not the best condition, but a place filler if you don't have one.

2) dry process recessed-marked CNR with sharp outer base edge and conical pinhole top. There is some tenuous evidence that these may have been made at the St Johns Potteries in St Jean, Quebec, but more reasearch is needed on this subject. This example has a glazed pinhole which is somewhat unusual for these. One faint black hairline bruise on the very base in the rear.

3.) Pittsburgh High Voltage-made example with bold, incused embossing and periods between each letter. This one has some asymmetry in the wire groove and some creases on the crown but is otherwise higher quality than most PHV-made examples. VNM with only some wire groove rubbing.

I'm now asking $17 USD plus shipping for the set of three. I'm always happy to trade for early Canadian glass or Canadian-made porcelain insulators. I accept PayPal, or personal cheque from any member of ICON or any collector with whom I have dealt before. Please feel free to contact me with any questions or for more photos, and look through my other items or unsold sales stock to combine shipping on items.