@neonknight, your picture looks the same as the one generally referred to as Kiwami.
Earlier discussions have suggested that the gold body Rex and Kiwami were identical and one of them was for export purposes. But if the correct tracking force of Kiwami is between 2.0 and 2.5 gram, than it must be different to Rex (1.5 gram per manual).
However, this brings to mind a similar situation with the Sato Musen Zen Diamond cartridge. There were two technically and cosmetically identical versions, perhaps also for export purposes. One has the word ’Zen’ and the other a Japanese character on the same spot. The only difference is the recommended tracking force......
I know this is highly speculative and probably too far fetched, but could there have been some East/West difference in playback practice that might explain this distinction?