Congratulations! the first step is to optimize. Contact Oracle Audio in Quebec and get the Maintenance kit with the correct springs for the SME. Carefully replace all the rubber and felt parts, the belt, and replace the oil in the bearing (flip the carbide pad to the fresh surface). If you are not capable to set up the Oracle, ask them to recommend a dealer..If the cartridge is not usable it can be rebuilt by Soundsmith or Andy Kim. But,
I would not recommend to replace the SUT. A better choice would be to ask Soundsmith to recommend a cartridge for your arm & preamp. My guess would be the Aida, with high output and medium compliance. The new Aida has an insert to permit setting the azimuth with an arm like the SME. Again, this will require careful setup which will yield bigger improvements than throwing money at equipment.
I would not recommend to replace the SUT. A better choice would be to ask Soundsmith to recommend a cartridge for your arm & preamp. My guess would be the Aida, with high output and medium compliance. The new Aida has an insert to permit setting the azimuth with an arm like the SME. Again, this will require careful setup which will yield bigger improvements than throwing money at equipment.