Plarail Line 0 Inside Curved Track

I spotted these curved rails on eBay; the seller calls them "Test Shot Plarail Line 0 Inside The Single Curved Rail Set":









I can't see Tomy's logo, so I suppose they are custom made, or printed, or whatever... But they seem to be very useful rails. As we can see, they can form a circle inside a circle made of usual curved rails R-03. Possibilities for using them in a layout are numerous. There is a gold variant too:







Did Tomy ever produced a small inside curve track like that? They produced the Outward Curve Rail R-09 (which is basically the same track as the outward curved rail in R-05 Double Curve Rail), but what about this little ones? I think that would be much used track in every kind of layout, especially in smaller ones...

Also, I always miss 1/2 Curve Rail. There is R-02 1/2 Straight Rail, but what about curved one? Was there Plarail 1/2 Curve Rail at all? I don't think I saw a rail like that. And they would be very usefull, too. For example, with those 1/2 curve tracks you could put a crossing on curve (or Pororon Station, or some other curved piece) right in the middle of the curve in an oval layout... like this:



What do you think?