All were ordered through Amazon. There were 4 last year with the 18 dBm setting, then another batch of 4 (one of which had the 18 dBm setting and the other three with 12 dBm), and finally a batch of 10 (8 have been examined and all 8 have the 12 dBm settings). I have easy access to the MAC addresses if that helps.
Example of 12 dBm calibration from /sys/kernel/debug/ieee80211/phy0/ath9k/regdump
0x00a3c0 0x1e1e1e1e
0x00a3c4 0x181a1c1e
0x00a3c8 0x20200020
0x00a3cc 0x20202020
0x00a3d0 0x18181818
0x00a3d4 0x1a181218
0x00a3d8 0x00000000
0x00a3dc 0x00000000
0x00a3e0 0x1e201e20
0x00a3e4 0x1a1a1416
0x00a3e8 0x00001416
Note register 0x00a3d0 giving the power for MSC0-5 of 0x18=24=12dBm
Thanks,