I want to know which of my favorited posts got deleted to try and salvage from the listed source, but all the pages of deleted posts are hidden from view. Is there a way to make them visible?

I don't think so unless we were to un-delete them and make them visible, which I don't think we do...so likely not

Try uploading them to the wayback machine before they get deleted, then you can use the link to view the screenshots of the post forever.

If it was recent, you could check the Deleted Index:
hypnohub.net/post/deleted_index

if you mean seing a post's image when it's deleted, you can go to hypnohub.net//data/image/[the post's md5].[either png, jpg or gif]
(the md5 is in the post deleted banner)

if you want to show deleted posts when searching by tags it's not directly possible sadly, but the pics are still tagged, so if you feel like going throught every single posts on the hub you could find what you're looking for