Hello John, this is custom hand-drawn Classic Roman lettering. At the time this monument was made hand-drawn lettering was still very common. Even after letter sets were popularized for creating inscriptions and hand-cutting them into the sandblast stencil, it was still common to see hand-drawn lettering used for a surname on a monument like this because most letter sets were not produced above 3.5″ tall.
If you would like help matching this lettering for a new memorial, you might be interested in using the Inscription Matching Service.
Additionally, you can use a somewhat similar font like the MLC Classic Roman SR font, which is based on the old metal Spacerite Classic Roman alphabet: https://www.monumentletteringcenter.com/product/mlc-spacerite-classic-roman/