Does the song contain these lines?
на Африка, на Камерун
как немцы говорят
=
To Africa, to Cameroon,
like the Germans say???
If the recording is from 1891, it would fit with Cameroon becoming a German colony in 1884.
A Russophone YouTube commenter says that the woman has a Danish accent in her Russian (sounds like that to me too), and that the man speaks with a "kartavits", i.e. uvular r (sounds like that partially to me, at least in the song). It certainly doesn't sound like the normal, modern Russian rolled r, more like a Swedish or Norwegian rolled r. In this case it could be German and French influence, but normally a uvular r is associated with a Yiddish accent in Russian.
Anyways, extremely interesting, thanks for posting.