These early recordings from Casablanca Steel band demonstrates the arc in musical development of the steel pan from the late 1940s into the 1950s.
Originally from a 10" Disc recording from 1947, the first tune "Medley" features an early calypso hit from that era "Brown Skin Gal".
The second selection, "In A Calabash",was recorded in 1953. This was the "Road March" tune for Carnival 1950, and a version was most likely played on the road that year by Casablanca.
These are some of the earliest steelband recordings available. They are from the collection"Casablanca Steel Orchestra - Trinidad Steelband (1947-1953)" which features two ten inch DISC recordings by the "Casablanca Steel Band" from 1947, and the SaGomes albums "Casablanca Steel Orchestra" recorded in 1953.
As far as I am aware, the 1947 Casablanca recordings are the earliest known steelpan recordings.