I would say to upgrade the tonearm (the wiring, bushings and bearings are old) and the Rega RB 303 is a considerable upgrade. The Rega is a longer tonearm, also a higher mass, so you would need to consult with your dealer on whether or not your table needs to be modified; by that I mean some cutting might be needed to accommodate mounting the Rega.
I have a Linn from 1988 and looked at the Rega 303, but it would not be a simple installation on my TT.
I have a Linn from 1988 and looked at the Rega 303, but it would not be a simple installation on my TT.