The current equivalent of the 103c is the 103. They dropped the c designation, but it is the same cartridge that they have made since 1961. I had one of those prior to my 103R. The 103R is way better. It has smaller coils of 99.9999% OFC copper, and slightly lower output, and sounds great.
As far as poor tracking goes, that is the fault of the arms that it is used in, not the cartridge itself. The compliance of the 103 is very low, and puts alot of energy back into the arm, and very few arms can really handle this cartridge well. The arm is really causing the mistracking that is heard with this cartridge. It needs a fairly high mass arm, with great bearings.
As far as poor tracking goes, that is the fault of the arms that it is used in, not the cartridge itself. The compliance of the 103 is very low, and puts alot of energy back into the arm, and very few arms can really handle this cartridge well. The arm is really causing the mistracking that is heard with this cartridge. It needs a fairly high mass arm, with great bearings.