Hello bigdawg.....
Welcome to the club.......
Stamps with opposing straight edges are called coil stamps, either horizontal or vertical. That type of cancel is called a 'pre-cancel'.....canceled before being used by government agencies as a security device to stop employees from trying to use the stamps on personal items. And, there are hundreds of cities & towns to be found on pre-canceled stamps.
It is not possible to identify a Franklin stamp from just a description or image because there are quite a few look-alikes for that issue. Also, you mention '11 perforations'.....this leads me to think that you are counting the perforations. Perforations and the spaces between them need to be measured with a 'perf gauge', not counted. Here' s a look at one type:

Here's another type of pre-cancel:

The time period for those types of Franklin stamps was the 1920 - 30's.
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