[crolick]

Summarizing the facts:
1) GQM lists He.59 as downed on 6 IX by Flak near Gdynia
2) Gen.d.Lw.b.Ob.d.M lists He.59 as downed on 4 IX by Flak near Hel
3) Volksbund.de lists Lt.z.S. Munscher and Uffz. Fuchs as killed on 6 IX near Hel

As for the Polish sources (though those ones are only based on memories of the Polish soldiers so not the original data):
1) kpt. Wojcieszek (CO of AA defence on Hel) claims that his batteries downed three enemy planes on 4 IX/04.30 (the same plane as in 2) ), 6 IX/21.00 and 7 IX/04.20
2) kpt Przybyszewski (CO of Polish coastal battery placed in Hel) claims that one plane was downed on 5 IX and that some parts were taken out of the water
3) kpt. Dziubinski (CO of one of the AA batteries on Hel) claims that he have downed one enemy plane on 6 IX/21.00 and that the glove and parts of the wing were recollected from the see