I'm due for a bit of book pruning myself...
Our current total chart count is up in the 1,100 range, and to date I have only pruned some 100 of those (mostly old, tired stocks from the early 1930s plus some moldy items from the 1940s).
With multiple acquisitions coming in the very near future, it's time to drop the duplicates (same tune, only by different arrangers), the majority of the non-vocals (my lead alto and I went to a Brian Setzer concert last night - over 3/4 of the numbers they did were non-vocal (or only girl backup vocal, clearly used as a fleshy ornament rather than for any musical value), and they were just not "interesting" either to watch or to hear), and the multiple key arrangements (most of the time, my singers gravitate to our "standard" version, rather than to an alternate key version). It's just so much dead weight in the box, never getting pulled or played.
My numbering scheme is the one I learned in my teenaged years. The matrix is set up by taking your starting book tunes, arranged in alphabetic order (with articles and such suppressed; "A Kiss In The Dark" becomes "(A) Kiss In The Dark", and is in the Ks) and numbering them with odd numbers, starting with "3". So, the first series of charts would include the tunes 3, 5, 7, 9, 11...all the way up to 327.
Then, any new charts are slotted in between these milestones, usually with a letter added to better space them out. A tune falling between the 3 and 5 charts would be assigned either a number like "3G", "2" or "2Z", depending on where the name falls in the alphabetic series already established.
Doing it this way allows for several things. including a more or less infinitely expandable number system (particularly crowded in our system is the "228" series of charts - we have a 228YA, 228Y"Oh", and a 228ZA to deal with). It also allows for a rough dating of the age of the chart - odd numbered charts date way back, even numbered ones in the middle distance, and the ones like "228ZA" relatively modern.
In the series of charts that we pulled this Saturday for an upcoming job, I noted only three tunes (out of a total of some fifty four to sixty charts, including some allowed for requests and the like) with odd numbers without a letter after them. Of those, two of them were part of our first job (when the book numbered less than a hundred charts).
(I forgot to add that we use "Oh" for the letter O and "Eye" for the letter I - no chance of confusing them with 1 and zero.)
I used to have people pull their own music, but we have learned that when we did that, someone invariably pulled the wrong chart (our Misty charts are all clustered around 230-something). Some of my sidemen are older, hearing (and seeing) impaired, so mistakes can be made.
So, we now bring all of the boxes (twenty two or so of them, vocals included), pull the charts (and resort the rest of their books in the process), replace any lost charts (vocal charts are particularly susceptible to this, as the thrushes have a tendency to "borrow" and not replace charts that need work), and sort them all into set order into our plastic, color coded set folders.
It's a lot more physical labor that way, but an approach that's free of any of the complications involved when entrusting something relatively complex to twenty-odd people. (It also enables a sub to come in the door and play the charts, without the complications of finding them in an unfamiliar book.)
But, Lordy, do I hate to break the trailer out and move all of those black boxes...
(Oh, and we get a lot more than $2,000 an appearance. Other than for a connected charity job (through one of our members - regularly charity jobs get billed at the rate card rates), I don't drop down anywhere near that figure. Still, you go with what your market will bear.)