Hi Chris, this is the ScotchKut Double Outline at the medium sizes, with the second outline removed and a custom ampersand. Based on the date it is likely that the actual plastic letters were used and the ampersand drawn by hand, or it the memorial was made much later in the late 1980s or 1990s, it is possible that this was a digital version.
The MLC has a version of the of the font available which has been bundled with a second font matching the plastic alphabets at the large sizes as well, here: https://www.monumentletteringcenter.com/product/mlc-scotchkut-double-outline-medium-large/