The stampings on this pipe demonstrate that the "Londonaire" label correponds to a line of the Calebresi brand.
Londonaire as a Calabresi line
Left side ▼
Right side ▼
It often happens the "Londonaire" stamping occurs on the left side of the shank without any other reference to a brand.
(See here)
(See here)
Global view of the Calabresi - Londonaire pipe ▼
Wilczak & Colwell op. cit. list the Londonaire label as from "House of Crane 1926" with a English or USA origin.