Your cartridges, if not worn out, are too old now to expect them to be at their best. Assuming proper care, the arms should be fine.
The Grace is a low mass design, which also lacks rigidity, due to the slim arm tube. It should be paired with a medium to high compliance cartridge for best results. I think a Goldring 1042 Gyger II would sound good in that arm.
The MMT arm is a medium mass, maybe even leaning towards the higher mass end if it is the "S" shape one. I like a Dynavector 10x4 MkII for that price range in this arm.
The Grace is a low mass design, which also lacks rigidity, due to the slim arm tube. It should be paired with a medium to high compliance cartridge for best results. I think a Goldring 1042 Gyger II would sound good in that arm.
The MMT arm is a medium mass, maybe even leaning towards the higher mass end if it is the "S" shape one. I like a Dynavector 10x4 MkII for that price range in this arm.