This is Condensed Roman Semi-Sans lettering. The metal Spacerite letters were likely used, and then most of the serifs were removed by the stencil cutter.
There is a version of a Condensed Roman Semi-Sans font in the MLC Font Shop, but it will not match this exactly, and would need to be modified in order to match more closely. Because the serifs were removed by hand, the specific serifs that were removed or left on varies from stone to stone. It also appears that the stencil cutter made the characters a little bolder while cutting.