As I go through some of the lots I've purchased, I found a couple of interesting cancels on some of the Postal Cards.
The first one, someone forgot to put the date/month slug into the machine canceler before operating it. It's from 1956, but that's all you get.
The next clerk was a little better at this, at least he/she remembered to insert the slug. Unfortunately for them, it's upside down.
The last one is a neat postal card use, although the "end of the Daltons" at the bottom is a wee bit macabre...