I talked to the records unit at the Butte County SO yesterday - they said that the new letters going out have an expiration of 60 days, not 30, and that mine was probably one of the last letters that went out with the old number. We signed up for a class at Safer Arms in early April and I think my personal situation is resolved.
In the bigger picture, I think it would be better to have a better-defined policy regarding expiration of the training letter. While I think it does make sense for the letter to expire, given that the two components of CCW eligibility (good cause and good moral character) are both subject to change with the passage of time, I think 30 days is too short (and, apparently, the SO has come to think so, too.)
By way of comparison, attorney licensing also requires a determination of good moral character. When the CA Bar makes a determination that an applicant is of good moral character, that determination is good for 36 months before it must be renewed.
While I don't think that it makes sense for the training letter to be valid indefinitely (the CCW itself is only valid for 2 years), I think it would make a lot more sense to say that the license must be issued by date "X", rather than saying that someone must complete registration for training prior to date "X". I don't have any reason to think anything bad about anyone at Safer Arms, but I'm not very comfortable with letting the time period expire before I have completed the training - what if the instructor dies, or goes on vacation, or the range closes or has a fire, or the instructor and I don't get along with each other? What if the training org decides to triple their prices after the letter expires?
If the concern is that someone will be eligible today, get a training authorization, then commit a bunch of crimes and get rid of the parts of their life that created good cause, and then go get their permit with stale/expired GC/MC, it doesn't make sense to say that the training org can extend the issue period indefinitely - that doesn't really address the underlying concern. It makes it a little tougher for the applicant, versus just putting the letter in their sock drawer and getting it out 10 years later, but if we're really concerned that unqualified people are going to get licensed, we can/should do better than that.
FYI, when we registered at Safer Arms for the class, they wanted to keep the original of the training authorization letter.
"[T]he liberties of the American people [are] dependent upon the ballot-box, the jury-box, and the cartridge-box . . without these no class of people could live and flourish in this country." -- Frederick Douglass (1892)