I think this might be your lucky day.
This Gallery has most Playgirl models, listed and depicted by name:
https://www.adonismale.com/gallery/category/5-dc-playgirl/
For full issues, you'll find almost all of them, from 1973 to when it stopped publishing, in the Porn Magazines section:
https://www.adonismale.com/files/category/137-porn-magazines/
You'll have to scroll through the latter to find Playgirl in among all the other magazines. It used to be indexed, where you could go stray to the "P" section, but a recent mishegas here rendered that unusable for the moment. I believe it's part of the fix that's still ongoing?
In any case, yes: this is the motherlode for back issues of Playgirl; something that brought a lot of us here.