Rebuild or new cartridge with my zeta tonearm

My only concern on the existing Sumiko is that it may just be a tad light for the Zeta.
It was originally about $850 new, not sure if I would spend $500 to $600 on a rebuild.
It will likely not have the same boron cantilever on return.
Now it is entirely possible that the OP may really like the sound of the rebuilt cart but is an expensive gamble IMHO.

My only concern on the existing Sumiko is that it may just be a tad light for the Zeta.
It was originally about $850 new, not sure if I would spend $500 to $600 on a rebuild.
It will likely not have the same boron cantilever on return.
Now it is entirely possible that the OP may really like the sound of the rebuilt cart but is an expensive gamble IMHO.

Even though I am not a huge fan of the Denon DL103, I believe it is reported to be a very good match to the Zeta arm which is built like a brick outhouse and weighs it...lol.

So that is one option IF you wanted to try the lomc route.

I very much doubt it will sound better than new.
It will definitely sound different.
It will definitely not sound the same.
It could sound good.
It could sound very good.