@mikeslr :-
I think you and peebee are, in fact, both right.
Bionic 64's specific 'curated' repos will remain together in their listings, but to access those repos as a set requires the editing of that file in Puppy which I, too, cannot remember the name of ATM.
At the same time, every one of those individual repo packages will also have been archived into /ubuntu/pool; this is where Canonical store every package they've ever built for Ubuntu. This list never gets 'trimmed'; it contains everything going all the way back to Ubuntu 4.10 "Warty Warthog" - released in October of 2004 - and at this point contains nearly 19 years worth of software.....
From what I understand of it, what happens when you select any specific package for any Ubuntu-based Puppy is that the URLs you then get for downloading those packages actually re-direct and point to the relevant page in /ubuntu/pool. So it's all kinda linked together anyway.
(Don't quote me on it, but as near as i can figure it out, I believe this is what happens...)
You can obtain those same packages manually, you need to search via dates instead. But there's no filters or Search function; you just have to manually search each and every list via their included dates to obtain the relevant package that would have been available for any specific release.....
T'other Mike.