Jail
Recreate the jail in WindRiver would be the ideal, with a private IP for access.
Previous names were Tronstad (T167) and Theyk.
Previously, it was a Debian GNU/kFreeBSD experiment. It can be a regular FreeBSD jail instead, as Debian GNU/kFreeBSD isn't currently an active interest.
ZFS dataset
Files should be stored on /datacube/ftp (create a ZFS volume), mounted too in the jail
devfs must be mounted in the jail to have access to ZFS datasets outside
SFTP access
Anonymous FTP access could be replaced by SFTP public access. Create an ftp-public account with a rotating, known password, or a rotating, known SSH key published, or some service with form to accept any public key.
With proper monitoring of uploaded files, it's OK. The main risk is to be used as a warez dump, but they bruteforce search for FTP public sites, and historically started by put a text file, and... that's it because if you delete it soon enough, they know it's not a stable storage to use. With SFTP special manipulation, it requires specifically targeted attack instead of bruteforce usual one.
FTPS access
No current use case. There is a good support from library, but if it's only to download, we expose a HTTPS mirror with an even better support.
Files content
A Google search on "ftp.nasqueron.org" shows there is no specific content to restore, as none is still referenced. In the past, some FreeBSD ports used it.
References