Yeah, I realized my spelling error the moment I hit submit. It's amazing how dependent I am on spell checker.
The garage is a pole structure that is detached from the house. I'm not sure I could get a bobcat in there due to around a 6-foot entry clearance level. So, your point concerning power shovels is well taken. I'm not sure if that was how garages were built in the 50's (no SUVs or big trucks) or it has sunk a bit.
With a 3" slab and a slope for drainage, what would be a sufficient sealant for the perimeter?