Where were Gustav Sprick and JG 26 based?

[Nick Beale]

For airfields, this is the place to look: http://www.ww2.dk/lwairfields.html

Here is a good (but not infallible) source for unit bases at different times: http://www.ww2.dk/air/jagd/jg26.htm

And the "Fliegerhaus" (house of airmen?) could well be a mistake for "Fliegerhorst" (aerodrome).

For the early years of JG 26, I'd strongly recommend reading Donald Caldwell's "JG 26, Top Guns of the Luftwaffe".