Well, dingle-berries.
While waiting for answers to my request for more info, I kept digging and comparing the first pics w/ my info, which is not complete by any stretch of the imagination.
I thought I had it down to possibly 2 knives based on the sheath stamping. It looks like the ring of words around the first class emblem includes the word "HEADQUARTERS NEW YORK CITY".
According to "600 Boy Scout Knives", which by the way, the author warns is probably not complete, this sheath stamp is rarer that the regular stamp, which is "NATIONAL COUNCIL NEW YORK CITY" and was only associated with 2 of the KABAR line knives. The problem with that is the 2 knives had 3.38" and 4.5" blades. So the first MINOR glitch in the giddy-up - sheath stamp doesn't match published info. But wait, there's more.
Three knives had 5.0" blades - BUT their OALs were 9.25", 8.66" and 9.25". Not a match with yours. Bummer.
There was a 4th 5-incher, but it had a 5.13" blade with an OAL of 9.5".
None match your measurements.
However, the plot thickens - the "2nd" 5.0", with an OAL of 8.66" is listed as the BSA Model 1553.
The ad in your link has the 1554 and 1553. The specs listed in the ad for the 1553 state 5" blade and an OAL of either 9-3/8" or 9-5/8". My screen resolution and eyeball status makes it difficult to determine which. IF it is 9-5/8", that would be approx 9.66".
IF we assume (oohh, I hate doing that

) a typo in the book an combine it with the ad info, the 1553 in "600 BSAK" MIGHT really should have an OAL of 9.66" not 8.66". Still doesn't match your knife, but it's in the ball park.
Your knife does NOT appear to be shorter due to re-profiling due a broken tip, so that's not an excuse for it to be THAT short.
Except for OAL, it matches a 1553.
It COULD be a short bladed 1553 (I doubt it - it would never have left the factory over a half inch short).
It COULD be another commercial Kabar model stuck in a BSA sheath - either being one of the many "unofficial" BSA knives, or being a Kabar knife stuck into a BSA sheath from another company's "Official BSA KNIFE" offering. The sheath does match the description of the BSA logo stamp "placement" (high up near the throat), but NOT the stamp that is supposed to be on the 1553 sheath. Well, stamps could be used on any sheath, depending on how harried/lazy the sheath stamper was that day.
It could be an OFFICIAL BSA knife that was not encountered by the author of "600 BSAK" and so is undocumented, until someone crawls through ALL past issued of Boy's Life Magazine examining all the ads.
This knife is also an example of why I totally detest "professionally cleaned". All the old (1920s-1930s) BSA knives had the OFFICIAL KNIFE OF THE BOY SCOUTS OF AMERICA wording, along with either the First Class or Tenderfoot badge etched into the blade. When the knives are "polished up" Kentucky mint style, any vestige of the etch is gone forever and you have absolutely no way to identify the knife as a true BSA knife. It may be a knife "like" the official knives, but it can't be proven.
I have several old BSA knives that the etching is so faint, either from use, excessive bad sharpening or corrosion, ANY attempt to "polish it up" would remove the proof that they were BSA knives.
So what do you have??? We don't know. GUNSIL may be able to identify it as to a specific Kabar commercial product, but the actual BSA model designation will remain a mystery for a while.