Which cart is damaged? The rc2 damper is not serviceable. If it's the ATA cart, that is very user serviceable. Upgrade the sliding seals to quad rings helps heaps with the Ata cart
Edit: is it 35 or 38mm version? 1 or 2 air valves on the top cap? The original 66 sl (ata) used a 'doppio air' cartirdge which is a bit different to the the later ATA2 cartridge, but still user serviceable.