Most guys here reccomend Flitz for the brass, I think. Your "AV89094" serial number (and the box) show it to be one of the later serialized knives. I don't know that it makes it more collectable, but it does make it more interesting to some. In part, it demonstrates just how many of these knives were made. Beginning with no alpha prefix, they were numbered to 199,999, then A00001 to A99999, then B00001, all the way to Z99999 before the second alpha prefix was added, AA00001. BB56321 is the highest I have recorded so far, and I have a very early one, #0326. Serialization began in 1977 when production was begun, before the official rollout in July of 1978, or the first catalog appearance in 1979, and ended sometime in the late 1980's, so really just the first ten years or so. I don't know anyone who specifically collects them by and for the serial numbers, but it does add interest. I had to acquire a spread of serial numbers to write my research paper posted here. That showed me approximately when certain production changes were made, such as the elimination of one of the cover pins, and changes in tang stamps.
Codger