Where would I find Merchant Seamen Records? (Foreigner in London)

I'm looking for a foreign seaman who docked in London in 1916 and died there. I found his death record which provides his residence at the time, it's a hostel. What I'd like to identify now is what merchant ship he was working on before he fell ill. Where might I find this? I'm only familiar with passenger records.

Thank you!

​

Edit: I didn't think I'd find it there but the National Maritime Museum had him listed on a ship, I think this might be him, lists him as Russian with the right age for the time. If anyone has more experience with researching merchant sailors, I'd love to connect!