51.4" long Williams stainless steel side rail set used on many games from 1961 to 1987.
Each of these side rails has a total of 9 nail holes (8 on the side and one on the top at the back), and 2 square carriage bolt holes (1 at the front and 1 at the back).
Please double check your machine to make sure these are the correct side rails for your game.
Williams reference #01-6600.