Torpedobuch of the 9. Schnellboot-Flottille

[VC54002]

Hello,

I recently bought this Torpedobuch (A book which was used to document all the maintenance, modifications, exercise shots and transfers of each torpedo). I have attached a page that documents the transfer of the torpedo from "Torpedobetrieb Swinemünde" to the 9. Schnellboot-Flottille since I'm not sure about what the numbers (68377) in the second row indicate.

I would really like to know on which S-boat this torpedo served so I hope that it is some sort of identification number of the boat but it could be the id. number of the "Torpedokommando" or something else. I suspect that it might have not served in any S-boat because, according to the book, it was never given a warhead and pistol.

Does anyone know what these numbers mean?