I think you got a very nice and collectible piece of WW2 memorabilia. Signature on the sword is
関住星谷義長
Seki-jū Hoshiya Yoshinaga
(Made by) Yoshinaga Hoshiya of Seki
The fittings are in good/very good condition, the sword is in good condition for a WW2 sword, and the sword has a distinct mei, and is from a known smith...its all good. I think if you Google the smith's name, you can find other threads discussing other swords by him. The issue of the surrender tag is a side issue, but I think its probably OK, just a bit less worn than we normally see. With a WW2 sword and fittings in good condition like this, the presence (or lack) of surrender tag has minimal affect on the value of the ensemble. I think most people would like to have the tag as evidence of the sword's history, but, really, the condition of the sword and the scabbard are the important things - which is why I think think its a side issue. In any event, it is a real location in Japan, so if you ever wanted to research the presumed former owner, it can be done.