US 20c American Flag Perforation Question

It was 1980 or so when my father bought these stamps for mailing letters and I noticed that a perforation hole was missing at a set interval (I circled the 2 sites and put an arrow pointing at the missed site). So I kept these stamps, it is an un-separated block. Any value in it, is it common?

common....best bet is use as postage.
Nothing irregular....just a broken pin.
Sorry.

It is a collectible EFO. I like to keep them. They aren't rare at all, but I wouldn't consider them common either. Nor would I use it for postage. But then again, I like to collect them, so it's a matter of what you like to collect rather than financial value. In general, they won't have any sort of premium. If you have a whole bunch of perfs missing, they might have an ever so slight premium, but nothing to write home about.

Some EFO collectors like to focus on the US "war perfs" era, when broken/worn pins were often not replaced and missing perfs were not unusual.

Most of the U.S. war perfs came from the electric eye Harris-Seybold perforators for rotary press stamps. This is interesting given that for many years the BEP was trying to correct perforating errors due to bad centering so that the electric eye was developed for this; but then due to war time conservation, the perforator perforating parts were not replaced very often so that messy rough perforations resulted.

khj.....a broken pin is not a EFO.
Please show me anywhere that you have seen a broken pin
on a common stamp (any stamp)sell individually.
From the beginning of perforation of US stamp....pins break,
bend, get out of alignment....nothings special for 1 pin.
Look at all the early US....what do you think causes unpunched
perfs??? Ans....Bent/broken pins.....do they command a premium??? NO
Actually a unpunched perf is less desirable.

I would keep it in my collection too, if I had one like it. It's not an Error, but more of a Freak or Oddity. It may not be worth anything to some collectors, but it is still collectable.

Robert