Ikeda IT-345 is made later but every comparison I - or others - made, the 64s always was the winner. Better in Tone, much better in physical presence ... well, it is the way it is. I think, the 345 is much cheaper made ... and that counts finally.
Well, the IT-345 matte finishing (not later CR version) is much better made than FR-64s, absolutely no questions about it, I have both. Even FR-64fx is much better made than FR-64s.
Users who own both 64s and 64fx commented on this forum before, it's hard to decide which one is better, the difference is not so clear ass you are trying to say. The FX and old IKEDA are more expensive tonearms than older 64s. In my opinion the FX series (64fx and 66fx) is better made than 64s and more user friendly.
Ikeda-San designed his IT-345 series with better understanding of the 64s issues, read J.Carr’s posts on audiogon (he knew Ikeda-San personally).
The mirror finish CR latest IKEDA are different, I don’t like them.