NOTE: duplicate topic deleted.
To answer your question - there's no repository with old binaries. If you downloaded the image from 2017 it should contain the emulators from that time, there's no need to download something again.
Are you sure you weren't using the standalone PS1 emulator instead of the libretro core ? Perhaps you changed some settings to speed up the libretro core, which are now not present in a default RetroPie image (old and/or new).