Never mind responding, after searching out all the info I could find locally and thru another source, it turns out that my dear "country cousin" had the answer. He said " if you paint it once , you're never done, no matter what type of paint you use " . Furthermore , he suggested that if I was storing a car that leaked oil or was going to be engaged in any activity that could lead to oil etc on the floor, that I might want to invest in a roll of garage floor covering for that area ( available from HD ). HOWEVER... the clincher was that he took me to his 10 yr old garage where his son and friends work on their clunkers and had me look at his floor. I couldn't believe it ! Sure there was a bit of staining from foot traffic etc, but essentially it was perfect ! The secret ??
Apparently when the contractors polish the slab, the process brings the "brine" to the surface which when it dries , forms a protective surface . I don't know if this makes any sense, and I'm sure that if it doesn't somebody out there will let me know, but I'm happy with leaving it the way it is now that I've seen the cousins floor