Yep that's a barbers notch in it. The true purpose of the thing is only speculations nowadays but lots of us consider them beautiful quirks of the blades of that era.
Those Clover razors have serious steel they are one of those little talked about brands, but they will flat shave circles around many better known brands, looks like a really good buy.. I would love to see a closer pic of the whole edge and spine together to be positive... But for $10 I would buy two hehehehe
Morley made some awesome pocket knives too. Barber's notch/hollow point same thing. That particular razor is "that" old. It's built like a razor many years its senior, but that one most likely dates from the '20's. Quote stolen from Alex at http://www.strazors.com Not a bad thing as steel was a lot better in 1920 than it was in 1820, or 1880 for that matter. That old razor looks right as rain from here. I'm with Glen, I'd buy two as well, three if they had 'em.
Don't make him any wiser, you might let him know that you're looking for more junk (great shavers Morley)