I don't think they were ever sold in the UK Andre, as Russ Andrews took Grace and Supex over from Linn in 1980 when the Asak and Ittok appeared and the G707 was prematurely pensioned off with honours.....
I have two 707's, one in good working order and with fine bearings (they were too fine for ham-fisted Linnies to be honest). I know what you mean about the headshell, but the Supex 900 doesn't upset it too much and modern carts like the OC9 have pretty inert bodies which don't generate upper-mid resonances in it like some mm's do. I'm just going to have to get the SL-150 going this weekend and fit my spare Supex into the 707....
Tear down these walls; Cut the ties that held me
Crying out at the top of my voice; Tell me now if you can hear me