level 2 psbx4r
level 3 fxbx4r
level 4 yxbx4h
level 5 scbx4h
level 6 xtb842
level 7 CSB8G7
level 8 TXB24H
level 9 1SB849
level 10 LCB8GW
level 11 5TBV4R
level 12 OLB84W
level 14 81BV47
level 15 45B2G7
level 16 GLBVG7
level 17 QLBVGW
level 18 ?5BVGW
level 19 MDBX4K
level 20 30B84K
level 21 N0B8BB
level 22 28B8G2
level 23 R4B8G2
level 24 HGB24V
level 25 7MBXGZ
level 26 W3B8G6
level 27 JNBX4K
level 28 92B249    

Thanks to Revolution readers steven karkenny and BENJAMIN G MACH!