First off this site is so awesome, I really appreciate you all taking time to help out!
I am in the process of becoming one of you, I am ordering a bunch of tools so that I can finally fix my headsets, freewheels or hubs, and of course bottom brackets. I have a fair amount of bikes so it seems worth while.
I will first try as some of you suggest and remove the driveside crank and see if I can get rid of the play by tightening with the pin spanner, then if the problem persists perform surgery on the whole BB.
To clarify there is no lateral play (side to side), only very little play when pushing forward (pedalling) and it seems to be present on both sides. It is again a relatively small effect but any play in this manner is disconcerting when mountain biking...
Again appreciate the feedback and when the tools arrive and I get a chance to play around with it I will update!