Help dating cup

[Leofox]

Thank you for your help. Was sold to me as late qing/early roc.  What is odd to me is that the rim of cup seems unglazed

[peterp]

Depends whether the rim was fired that way or whether the glaze was removed afterwards.
What I find more suspicious is the cuts in the foot rim. I have never seen this before. These are cuts that must have been added with a sharp tool before firing.
It looks unused, without any age or usage signs, otherwise. Not sure if this is antique or not.

[Leofox]

Thank you for your help. I want to add that after receipt of the cup, I soaked it in a solution of sodium percarbonate for several hours, which cleaned it up.

[Leofox]

One last picture from the top. The inside looks quite clean except for 2-3 light rust spots