Attached below is the "after market" rocker arm oiler that will only work on heads that allow access to plug in the upper middle of the head (at the middle of the rocker arm assembly). I gets the oil feed from a by-pass oil filter T-fitting.
Good find Tim.
The '53-'60 time frame corresponds with the advent of the full pressure 235 introduced in 1953 in Powerglide equipped cars. I have one of those and there is the plug in the head.
