It took some time for me to figure this out (slaps forehead). I should have been more observant. The initials LB stand for designer Luigi Badia.

I know of two RHM products with his initials on the obverse.

1992 dated Princess Kaiulani 1/10 oz  silver

1991 King Kalakaua Akahi Dala 1/oz silver

 

Here is a plaster model  of the obverse die with the LB initials.