The mating beetles were sighted on the side of a concrete retaining wall, with the final image showing the correct orientation. Both beetles together were less than 10mm.
@MichaelMulvaney Hi Michael, I looked at this yesterday and looking on iNaturalist, I don't this is right. I think it is more likely Novius cardinalis. See https://www.inaturalist.org/taxa/1065202-Novius-cardinalis