Grace Tone arm

I have a Rega Planar 2 turntable, roughly 1980 vintage with a Grace 707 Mk II arm and Denon 103D cartridge. As old as this package is, it still sounds wonderful with the rest of my system (Marantz PM84D Int Amp, Vandersteen 2Ce spkrs) and I enjoy playing some old LP's every now and then. The arm lift mechanism for the tone arm broke some time ago. Does anyone know where I can get it repaired ? Thanks.
I have a spare tone arm lifter but don't know what it is off. Can you measure the diameter of yours? I will look at some old Grace literature to see if it will work (I used to be a Grace, Denon dealer) and let you know.
i have a perfect-condition grace 727 that i pulled off of the oracle i bought a while back, if yure interested... make me an offer! :>)
I have a Grace 707 with a Denon 103D. The turntable is an old technics direct drive. At the time it was made it was one of the better models. The bass response is very weak. The highs and midrange are very nice. What could be wrong?