They had someone come in and do some sort of topical and they said it is doing well. They want a bid from me to do the same which I will do shifting all liability of possible short lifespan off to them. 

I was thinking of using TK6 from Richard James, after prep sanding with a 120 or 220 nickel pad. or a random orbital with paper. I have to see what the sealer will fill in. 

Any ideas regarding methods, prep, application pads, etc?

This is the stone, like a white breccia something.