I am not sure I understand why you see a difference in the ingredients.
The bottle of TCP I have in front of me manufactured by Chefaro in the UK states:
Halogenated Phenols 0.68% w/v, Phenol 0.175% w/v, Glycerol, phosphoric acid, and E104
The 3CP label states:Halogenated Phenol 0.695% w/v, Phenol 0.175% w/v, glycerol, sodium salicylate, phosphoric acid, and E104.
There is a very slight difference in the quantity of halogenated phenols of 0.015% and UK TCP does not state sodium salicylate. The reason for this is that the UK manufactured version does not use the original South African made TCP formula, and if you saw the old SA TCP label as well as the MCC registered formula one would see the inclusion of the sodium salicylate.