Re:Kirkor's Legia Nadwiślańska 1808-1814:
I assume you refer to footnote 63, which is on p 300. A slight correction: it is S.H.A., cote C8-369 [i.e. 369, not 368]. If you look on pp. 563-564 - Tablica Nr 21. you will see a list of officers who were on 1.xii.1812:
With the Grand Armee [i.e, in Russia];
In Sedan [i.e. regimental depot]; and
In Bayonne [i.e. the Spanish depot].
Pages 323-342, part 4 of chapter 4, concerns the 7th in Russia in 1812 in great detail.