I don't know if this bears any relevance but it is worth considering

http://www.electricscotland.com/history/prussia/part3-2.htm
[index http://www.electricscotland.com/history/prussia/index.htm]
Scots in Eastern and Western Prussia
Part III – Documents (2)

List of Scotsmen who became burgesses of Danzig
includes
1598 Jas. Greger

List of thirty-seven Scottish Kramers attending the Fair at Wehlau. 1644.

includes
7. Th. Gregor.

Thomas Gregor also on page Scots in Eastern and Western Prussia
Part I – The Scottish Trader (3)

Jane