It kind of looks like there was a ( complete) paver brick pad made below it, on which it stands. (?).
If thats the case and it is a complete paver pad. Might be better to knock down the whole grill and just keep the paver brick pad underneath and use a standard stainless gas grill on top.
Usually masons will do a project with the same kind of bricks, when doing it at one time/period. It almost looks like a pad was there and then a pit was added later with a different style of bricks.
Wish I was closer to your location, I could help you out, better.
Good luck