Like Tim
@trc65 said, it's pretty easy to grind your own if you have an "extra" scraper on hand. I use tenons almost exclusively, however, our turning club inherited a bunch of once-turned bowls and the former owner used all motices, (or recesses). There was a lot of Cherry burl once-turned bowls, so I took a couple to finish.
Anyway - I would usually use a skew to re-round the recess, but it doesn't always work because the tailstock is sometimes in the way to line up the skew (unless you have a vacuum chuck). The skew has to have the handle swung slightly to the right to get the correct angle at the tip. I have found the home-made tool to be a little "grabby" compared with using a skew, but I've used it in a pinch.