An Unusually Wide Spaced Precancel From Chicago, IL

I'm usually quite intimidated by Chicago L-type precancels, because there are such a vast number of them and I don't have the proper catalogs needed for identification.

However, I came upon this example that I thought was rather unusual (maybe not?) because of its unusually wide spacing. In fact, I measure it to be approximately 20 mm between the bars; 3.5 mm high letters and a full 6 mm of spacing between the city and state name:



If anyone is familiar with this specific precancel, I'd like to be able to identify it.

Thanks.

Probably L-18 but would have to compare it with a known copy to be sure.

Thanks. At least it's a start toward identifying my Chicago precancels!

And not a 20c, either, wt1. Very cool.