Putative L. heuglini in Czech Republic

[Michal Sindel]

Hello,
Please, can you help me with identification?
I took a pictures (October 13) of a gull on which I believe it is larus
heuglini. I took the picture (digiscoping) on the water tank near the landfill waste near
Ostrava city in Czech Republic (its only few kilometres from borders of Poland).

Why I think that it is L. heuglini?
1. The gull is in summer plumage while L. fuscus int/gr. is in this
time in winter plumage it means with head-streaks.
2. The gull is very big (the same size like larus michahellis and L.
cachinnans), with longer bill (obvious gonys-angle, thickening at distal
part), small head, slender neck
3. very small white tips to outer prim-tips

I am sending you also some photos of L. fuscus fuscus and L. fuscus
intermedius/graellsii whose I made in the same day.

Thank you very much

Michal Šindel