An interesting question, to which I too would like to know the answer!
My paternal grandfather, Józef Dudzinski, was manager of the Tsar's estate at Spala probably from the early 1880s until 1910... The earliest document I have is dated 1871, so it could be that he started working for the Tsar even sooner.
Unfortunately, most of the contemporary documents I have are in Russian and either handwritten or in a handwritten typeface, and I can just barely follow some of the Russian from its similarity to Polish. Quite a number start of them off with "Bozheyu milostyu, my, Nikolai Vtoryi, Impertaor i Samoderzhets Vserossiyskiy, Tsar Polskiy, Velikiy Knyaz Finlandskiy,...", and it would be nice to know what they say thereafter.
I'm trying to find someone to translate them for me or at least give me the gist.
However, I would be very interested in finding a photo or painting of the Spala hunting lodge. I've not been able to find more than fragments of the place on this website or elsewhere.
Sadly, there's no longer anyone else to ask, as everyone from my father's generation and beyond has now died. And as for my grandfather, I never met him as he died after being kicked in the head by one of the Tsar's horses! (I have the bill for his funeral: 46.60 roubles)