The Rumsey Westpex Sale has a purported RS173i vertical pair created from a cut-down and reperforated RS173j. The genuine imperforate pairs are horizontal pairs, imperforate vertically. Here is the Rumsey lot #2510.

Revcollector and I previously had a discussion about these fakes
https://goscf.com/t/82451&whichpage=4 when one was in a Kelleher Sale in January this year

lot 974 sale 2003
And here is another fake that was in a HR Harmer sale a few years ago
https://goscf.com/t/50895