Well well, coincidence. I tried to ascertain the eff. mass of my 12" Ace Anna by phoning Penny and Adam at N.A.. and she/he was only able to guess that it would be around 14/15 (not really helpful, I thought at the time). Realistically, Ks need a bit more than that (>20g), though they're not as fussy as a Miyajima !
I can't remember my Blk. Goldline on the unipivot, but the Vermillion was the first cart. to go on my A.A., which was my only arm at the time. I later changed it to my 12" A.O. PU7 and concluded that it much preferred the gimballed arm. My previous Benz Ebony and my current T. Proteus sounded different in each arm but equally as good. My PU7 is round about 14/15 g as well, according to Johnnie (each one made to order).
When I get round to it I must re-mount my Vermillion, which has been languishing in a drawer for some years, but can't face removing the Proteus from the PU7 and loth to put it on the A.A. because of my 'findings' some years ago, so it means setting up 2 cart's, and even with a Dr.F protractor, that'll be struggle (eyesight and age). I loved my Vermillion, but the much lower output c.f. the Blk did take a bit of getting used to, as the Blk was such a gutsy beast at 0.6V.
I don't know your arm but have heard of it. With that wand, it sounds similar to the Reed 3P 12" (which I have considered as my local dealer friend stocks it)