It's interesting how these things seem to come and go in waves. From 2002 (when I first started collecting revenue stamps) to 2013, I saw zero examples of R115a in the wild, despite having acquired 4-5 examples of R112b, the 25-center sewing machine perf, which at the time actually catalogued higher.
In mid-2013 I picked up my first R115a, a straight-edged example that Bart clued me in on from a show dealer. I traded it about 4 months later in part for the superb example from the Morrissey exhibit. In January of this year I cherrypicked one with a double transfer from
ebay, was outbid on a second one within a goup lot, and now this one.
I need a wave of the $1.50 sewing machine perf to come through...
EDIT: Apparently the "wave" is fewer examples than I thought. I just looked back at the lot that I was outbid on in January (the listing and images are still out there on
ebay), and this is that very stamp. So apparently the person who bought that lot didn't do it for this stamp, or it wouldn't have been priced as it was.
So even though I was disappointed at the time at being outbid on the lot, I ultimately ended up with the stamp I wanted, just without spending $300+. Go figure.
Things have a way of coming full circle.