AI is very good for finding old threads IF you know, exactly, the title of the thread you want to find. Using "Question about a Parker" is not going to work.
If you want to find an old thread with a particularly helpful (or insulting wink ) statement, you can use Wayback Machine.
I was able to recover part of Pete Mikalajunas' invaluable Damascus Barrels site after his death and the site went offline using Wayback. The images however were lost.
https://damascus-barrels.com/

SO to search for an old thread on the Forum using Wayback machine use (you will need to cut & paste to your search engine ie Google Chrome or another)
https://web.archive.org/web/20260000000000*/https://www.doublegunshop.com/forums/ubbthreads.php

This screen will pop up. Note that Forum posts back to 2007 are archived

[Linked Image from photos.smugmug.com]

Click on the year you want, pick a date, then click on the time the bot archived the Forum; ie August 26, 2017
https://web.archive.org/web/20170827033116/http://www.doublegunshop.com/forums/ubbthreads.php?ubb=postlist&Board=1&page=1

[Linked Image from photos.smugmug.com]

Note, just like today, in the upper R you can click on previous threads and search several years back.

It's a bit sad, and confirmation that I'm a lot older, to see some of the valuable (or not smile )posters who are no longer with us, by choice or by death. I would observe that it is considered very bad form to claim someone who has passed or left said something without providing the actual quote and link thereto.

https://sites.google.com/a/damascusknowledge.com/www/home