Commemorative Precancels

I know modern precancel regulations generally prohibit commemorative stamps from being precanceled (although some of the modern Christmas experimentals are another story...perhaps another reason why Christmas stamps may not be considered commemoratives, but that's for another thread.)

Anyway, I know there are a few early precancels that were applied to commemorative stamps back in the 1930's. Here's one example (Scott #773) with Torrington, CT precancel that I believe to be a Precancel Type 247. Is this a common occurrence for that period? I'm particularly intrigued by the partial city/state name overlap before and after the central one, because the precancel used on an "oversized" commemorative stamp as compared to a regular issue:

Precancelled commemoratives (and air mail) are pretty common especially 1930's and 1940's.

Thanks. I have a few of these (but not too many). Interesting precancel imprint, though, as you can tell it was designed for a regular issue and just applied to the larger commemorative format stamp.