I haven't been able to find this stamp in my Scott catalog or on various stamp ID sites I usually use, and I can't find where to stick it in my Steiner pages.
Is it part of some random set, ss, or booklet? Was it from an earlier year?
The set is Scott #3028-3036. The 1st regularly perforated is 3028 if photo, and 3028a if litho. The booklet stamp is 3036. ALl the stamps have perforations. Unless you posted a general picture of the stamp, you might have a postal stationary cut out.