missing letter in Lewis Des. #

[chicago dave]

ser 5970
des. L 11B-42 (not BK)
HP 65
rpm 2350
T.C. 788

[Dave]

ser 5970
des. L 11B-42 (not BK)
HP 65
rpm 2350
T.C. 788

Not sure why a K wasn't stamped, but there were a lot of variations. I suspect it still belongs with the "k" stamped uses.