[Cronos]

I have no idea who you attribute those words to. But Peter used the keys by announcing heaven’s decision, there are no more. That is evidence of Scripture.

Scripture doesn't say that that was the end, does it?

[count-your-change]

First...Do you think I have the tense wrong? That is, Had these decisons about opening the way for Gentiles and others into the kingdom already been by God and Peter was announcing those decisions thus using a “key”?

No, it was not said, “There are no more”. If more “keys to the Kingdom were used then the question is what and where and by whom?
Calling something a “key to the kingdom” would indicate those locked out in some sense were now able to enter the kingdom.

Is there some situation recorded in Scripture that would unambiguously indicate Peter was using other “keys” beyond those three instances recorded in Acts?