I have a post I wanted to get back to and add more info to my op but I cannot, is there any way I could get permission to edit the OP indefinitely?
Pretty sure PW set the time limit at 48 hrs. After that, "It's history".
You're better off adding a new "reply" to your existing thread, and quoting your OP in it.
That way your Rest of the Story will show up as a new post to readers. If you just modify your old post, it won't be flagged and chances are nobody will go back to "old news" and re-read it for the new info.