Here is info from my CRK Timeline Sticky, check it out !
A slabs made from January-April
B slabs made from May-August
C slabs made from September-December
So A99 would be made in say February of 1999; B03 would be made say June 2003; C09 would be made say November 2009............It goes like that, just examples !
They make the scales and stamp them. Then when they make knives, they grab 2 scales and go to work. There are times at the end of a run form the "A" batch where one is left over. They are definately going to use it, so this is when you see one from one batch, and one from another. This happens every once in awhile on new ones. probably more often on pre-owned ones as people switch things around. Not saying that happened to this one. It is very possible it left CRK this way.