Paddle steamers on the River Aa in Latvia

[AlistairD]

Does anybody know anything about the paddle stamers that ran on the River Aa, now the Leilupe, and which ran from Riga to Mitau, now Jelgrava
I have recently been reading Racundra's Third Cruise by Arthur Ransome, (or more accurately a book recently constructed from his notes and logbook), an account of a trip there by his sailing vessel RACUNDRA, which mentions steamers several times, and the names ANITA and ADLER for two paddle steamers and CONDOR for a screw steamer.
There are photographs in the book, but only one with a steamer in the distance, a small single-decked affair with fore and aft deck saloons