Hello, what you’ve got in the first image is a custom version of the Government alphabet used on Veteran’s headstones, which was a set of metal letters and numbers developed in the 1940s for the government by the Spacerite Company. Before this time the alphabet used on these government-issued headstones varied from manufacturer to manufacturer, but it was eventually decided that there should be a standardized lettering style. The main differences between the original alphabet and what was used for the memorial in your image can be seen in the numbers. I have seen evidence that the Spacerite company did produce custom versions of the alphabet, and due to the amount and consistency of the lettering on this memorial, a physical alphabet was almost certainly used to transfer the lettering to the sandblast stencil. You can read more about the Government alphabet here: https://www.monumentletteringcenter.com/product/mlc-spacerite-government-font/
In the second image, you have an entirely hand-drawn and hand-carved custom lettering style. This would have been designed either by Gehron and Seltzer—the architecture firm who designed the memorial—or possibly by the quarry/manufacturer the granite was sourced from.