In the 1938/39 Einwohnerverzeichnis for Marienburg we find eight listing under Porsch. It's in the Gothic German print. So with the aid of a Gothic print sheet and a german translation site this is what I've come up with.
Porsch
FIRST NAME OCCUPATION ADDRESS
Bruno - Urb., Breussenster 47
Gust. - Schreibgeh / ?Scribe, Ulmenweg 10
Hilda - Um., Topfertor 7
Joh. - maurer/bricklayer, Gneisenastr 9
Johann - Urb., Gtr. 25
Julius - Zugfuhrer / Conductor Ulmenweg 109
Karl - hausdiener / hotel servant, Welsch Gart 11
Marie - Ww., Preussenstr 47
I'm not sure what Ww., Um. or Urb. stands for. Ww. might be Widower. I'm off to find out.
I note that Gust. and Julius both live on Ulmenweg, but it may be a way apart. It'll be interesting to find out how many are related to each other. Only time will tell.