Yes, it is the same material; it's just Van's internal part numbering system that they've used for decades. Section 4 of the KAI is helpful for deducing these, i.e. AA6 is 0.63 X 3/4 X3/4 6061-T6 aluminum angle, which is the same part as 03-00185 from Aircraft Spruce.
Having bought both and compared them side by side, I can confirm they are the same.