Dual CS 505-1 tone arm upgrade?

I'm interested to upgrade the tone arm on my Dual CS 505-1.

It is my understanding that subsequent versions 505-2 and 505-3 had a superior ultra-low mass tone arm, with a better head shell that allowed for proper and more-secure cartridge mounting.

I am also open to suggestions of other types of tone arms that might fit well on a CS 505 deck and might offer a more significant sonic improvement.

I would like to know, in the opinion of the community, if this upgrade would be worth the effort. If so, what is my best bet for procuring a new or vintage tone arm?

Thank you for considering this question.