Hi Mal - Sorry it has been a while since I have been on here...
That looks more like viral than bacterial to me (localised, slow growing and the fish act fine) - nothing can be done in general.
The sore in front of the eye could be related - (underlying tumour)
It could all be exasperated by stresses due to the territoriality of these fish - either way, it is not that deadly and just increases slowly with age.... but generally not deadly on its own unless a tumour grows int he wrong place.