WANTED: Any information on this mystery knife

[CycleSpectre]

Hi all,

(I HOPE I PUT THIS IN THE CORRECT SUB-FORUM)

Found this oddity at a local estate sale and want to track down what it is exactly...any information on it really.

The home I purchased it from was certainly not a home where a knife collector had lived...there were no other knives. This piece was found amongst boxes of tools and various fasteners in the garage.

It is shaped like a dagger. It is not sharpened. Satin finish. When observing the end of the tang, this blade appears to be cast. The plastic handle is removable and there is a metal tail-like pull tab at rear. The handle on one side is marked "JOHN GIBSON" and on the other "Remembrance (R) B&B ST. PAUL, MINN U.S.A." The tang is marked with various ounce weights as well as "KDC" within a small shield/hallmark. Where the tang inserts into the handle there appears to be some sort of copper metal housing.

 

[Centermass]

Google Fu says It appears to be a postal scale/letter opener called “The Postmaster” from the Brown and Bigelow promotional company of St. Paul. The handle shifted to adjust for the corresponding ounce weights on the tang. If I understand correctly, the knife was placed on the table, with the letter on the blade. The “guard” is the fulcrum, and you slid the handle out until the blade, with the letter on it lifted, giving a general weight.

ETA: It was probably personalized for John Gibson as the owner/recipient, if I had to guess.

 

[CycleSpectre]

^thank you so VERY much!!!!
I tried google searching to no avail.

 

[Centermass]

Reading the instructions on that site I forwarded you, looks like the letter actually got clipped in the clip at the end of the handle, not on the blade, and the blade is actually the counterweight. That makes more sense since the blade would be vertically oriented.

 

[CycleSpectre]

Is the little hole on the end of the tang for something in the handle to clip into or for something else?