From what I was able to find, the 721 does indeed seem (essentially) the only recent Panerai reference with a non-California, anonymous dial.
To be precise, there exist a few other "anonymous" references, such as the Pam 350 and 528 (pictures below taken from the web). However, these and related references (which I think are part of a "Lo scienziato" series) are all openworked, so we can barely speak of a dial and I don't think they should be part of the same discussion.
Otherwise, as I said, so far I have found NO other examples besides the 721! ;-)
To put things a little more in context for the interested reader, especially on the historical side, let me also include a nicely-written article that I found online on this topic, due to Perezcope:
I'll probably look further into this, as it was good to learn something interesting/curious on Panerai, a brand that I know only superficially. Thanks again for now to all those who contributed to this very nice thread!
Cheers.

Reference 350

Reference 528