I climbed Mt. Brewer via the East Ridge route (class 2) on 6 September 2009, and it was obvious that the true summit is approximately 100' to the west of the class 2 blocks on which the register is currently placed. I would rate the true summit block class 3+ (after free soloing it). I found it solid, easy, but completely exposed to a 25 foot fall (minimum).
There's a good picture of someone else downclimbing this block already attached to this page.
Yes, you are correct. Thanks for pointing this out!