Hi Mary Ann,
While visiting a Franciscan church in Krakow quite close to Wawel, I purchased some books. One is a history of Bernardines in Poland, volume III, from 1772-1946. The author is Jerome Eugene Wyczwski, OFM, and it is published by Calvarianum, Kalwaria Zebrzydowska, 1992. I checked the extensive Index, but there is no listing of Soja or Stopka. It could be that your relative belonged to a different Province of Bernardines in Poland. Here is their web-site:http://www.bernardyni.ofm.pl/
You might try to contact them and ask for further information about other provinces and friars.
I didn't find the attachment, so I couldn't see the photo. I'm wondering whether he might not have been a Conventual Franciscan ("Black Franciscan" from the color of the habit they wear). In Poland, these are called Franciscans; the "Brown Franciscans" (OFM) are called Bernardines.
Hope this helps a little.