The ps1 refcats at NSCA (and copied to USDF) were converted to version 1 in April 2019. I don’t know if we still have a public place to download them from (131k files, 400GB), but we probably should (for these and our htm-sharded Gaia DR2/DR3 files as well). We used to host a download link for PS1 on NCSA.
To run the convert script, you’ll have to use an older science pipelines release: I don’t know how far back you need to go to get a working version of the convert_refcat_to_nJy.py script, but I believe it had bit-rotted before I removed that script at the end of June on DM-34793.