The Hamilton Vantage was a very popular model being first released in 1958. It is one of the few models that can be found with a 500, 500A or 505 movement.
My example below has the 500 movement and the white dial — there was also a black dialled version. The case is 10K Gold Filled and the lug size is 18mm. The second hand on this example is not quite correct; it should have a red tipped arrow head.