I can't tell from the pictures but if you see it in person one way to tell old pottery from newer pottery is to lick it. The faster it absorbs the liquid the older it is. Strange but true.
I don't suggest running around licking pots, but this is a little known tool you can use to help you make an informed conclusion on pottery you think may be old.
You may be right on some forms of pottery. and the test can be affected by the type of climate the pot was found or kept in among other things. I can tell you that I collect Anasazi pottery and use this test often. The test was taught to me by a very well known archeologist who's specialty is southwest indian tribes. I should add that a good forger can make a pot that will quickly absorb moisture and that's where knowledge comes into play. On the other hand he could be sitting behind his desk chuckling to himself thinking about me licking pots. lol