I have been in touch with some of the more knowledge people regarding Tokai and have collected info since 1999 (including some interesting japanese books). I have the intention to finish my Tokai book anyday so I need to be as knowledge as possible but I am not able to write it in english so sales are very limited and no viable from a economical standpoint.
And yes I like to compare parts here and there and see how similar they are. Once, talking with a semipro guitar friend of mine and very knowledge, told me once he preferred a tailpìece from Tokai (original) over some other well known manufacterers and I trust him.
I have a similar one on my parts bin and will do the comparison very soon.
While at it, do the comparison for the STUDS also. I mean, if you have stock studs on the other Reborn, and these are STEEL as Pigtail studs are, my bet - which part will be contributing more to the tone of truly vintage voiced guitar - would be on studs - stock vs Pigtail (IF both are magnetic steel, whether nickel or gold plated), not on tailpiece - stock vs Pigtail (IF both are aluminum, whether nickel or gold plated). My ears tell me that the aluminum used for tailpiece has not changed much since '50s, but 'cold rolled' steel being used for studs is audibly different. And I do not have experience with MIJ guitars, and stock hardware used on them, so I do not know if studs used for top models like Reborn is actually magnetic carbon steel and not brass. Just check with the magnet.
Just try both studs keeping the same tailpiece on the guitar, whichever you chose/prefer. It's even easier than tailpiece change, you can just loosen the strings enough, they stay on tuners, unscrewing studs 4-6 half turns, first top then bottom one then top then bottom one again, until they are out of the guitar, replace studs then screw them one by one 4-6 half turns each. Hope this description makes sense to you. And keep the break angle of strings at bridge constant, but I guess you know that already.