In 1963, he was the Sub-director and Resident Director of the Consolidated African Selection Trust Ltd. (CAST), which operates in diamond mining.
He was brought to Leopoldville by Henry Templer Alexander, the then Chief of Defence Staff of the Ghana Armed Forces.
Welbeck's residence was besieged by the Congo military upon allegations that he was plotting against Mobutu's regime with the then deposed Patrice Lumumba.
That same year he was appointed Minister for Trade and Industries and he remained in that position until 13 January 1972 when the Busia government was overthrown by the SMC.
He also had a traditional marriage to Elizabeth Oheneba Akua Asafu-Adjaye with whom he had five sons (Alan, Richard, James, Mordecai, and Michael Quarshie).