[Sangetsu]

It's not a shin-gunto, or anything of the like (I've owned several). The only thing resembling a WW2 Shin-gunto sword is the handguard, and the lanyard ring at the end of the hilt. Shin-gunto swords never came with wooden scabbards.

In the first picture the temper line is obvious, and I can make out that the steel is laminated. Shin-gunto swords were not laminated, nor were they tempered, the blades were stamped out of the same material as railroad rails.

Next, I doubt anyone would to go the trouble of attaching an address tag to a WW2 Army-issue sword. A typical Japanese kitchen knife would be more valuable.

Here are a few easy ways to spot a shin-gunto sword. First is the materials. Shin-gunto swords come with steel scabbards (painted green), with the end stamped flat. The hilt will be made of cast aluminum (usually, some were made of copper, and a handful were made of patterned wood), with an embossed pattern resembling traditional cord wrapping, and there will be locking catch which must be pressed before the blade can be drawn. Most Shin-gunto swords will have an armorer's mark on the blade just above the brass collar, and usually the blade will have a blood groove which travels it's full length.

The blade is the important part, the fittings have relatively little value. During the war some soldiers had fair-to-good quality blades mounted in Shin-gunto type fittings, which, though cheap and unattractive, did a very good job of protecting the blade inside.

You should remove the hilt and see what the tang looks like underneath. Removing the hilt is easy. Make sure first that you have the sword in it's scabbard, then drive out the peg in the hilt. Hold the sword by the hilt tightly with one hand, the scabbard pointed straight up. With your free hand, strike your other hand (the one gripping the hilt tightly) with a downward motion. This should free up the hilt, and allow you to remove it from the tang. Most blades will have a signature or other mark engraved on the tang.

Do not remove the hilt without first putting the blade in it's scabbard, and make sure the edge is facing away from you.

Provided that the rust isn't more than a discoloration, that there are no chips on the edge, and that no one has tried sharpening the blade, it could be of decent value.