Anyway, I've not found much about P.O. Melby and his business. There was an embalmer with the name of Melby licensed in Illinois in 1913, but that doesn't seem to be our guy. There's a Si Melby Hall at Augsburg, but I haven't been able to connect him to either pro wrestling or preparations for eternal slumber. There also is (or was) and dorm called Agnes Melby Hall at St. Olaf, which allegedly was haunted. So, having found a ghost with a superficial tangential relationship to our sign, I guess I'll rest.
Of course, as soon as I've penned a few lines that amuse me (which I now steadfastly refuse to delete), I find a bit about our man. Peter O. Melby immigrated from Norway and ran his undertaking and cabinet making business from this location for 34 years until his death in 1921. That likely makes this sign 100 years old or more.