Is there any chance that your Phillip Steinmetz might have had a sister (born 1726, Prussia; died 1797) named Maria Magdalena Steinmetz? She married Jacob Steffens. I am a descendant of hers and I thought it quite a coincidence in the name Maria Magalena. Also, she was born within 4 years of Phillip. Please write back if this may connect to any info you have.