Help Identifying A Milwaukee Precancel Type

I have the following stamp which I am assuming is a precancel but cannot match it to any of the types listed (standard, bureau or local). I have a fair number of other types for Milwaukee and the font spacing doesn't match. Its close to L-5, L-6 or L-7 but this has a comma. It is a 1911 Perf 12, which according to PSS catalog limits it to type 512, or L-5 TS but it doesn't match either of those. I could be a post cancel as well but not sure.

Thanks!

box postcancel

While it is possible this could be a box post-cancel, the lines do not resemble any box cancel I've ever seen. Usually, those lines are about the same width as the lettering; these are very thin, and more reminiscent of a precancel, so I understand your being a bit puzzled.

I would still send the image to the folks at PSS (Precancel Stamp Society) and ask their opinions.

Ideally, you could write a short article about it, send it to the editor of the journal and ask him to publish it. Someone will respond to the question of "What is it?"

If nothing else, you'll spend an hour writing a short article and sending it. Who knows, it could be something newly discovered. Wouldn't be the first time.