A Brief History of the Marque
Lamberto Landi produced a motorcycle named The Sweet (la Dolce) powered by a Train engine.
A 1925 advertisement reads,
"....la piü antica Ditta che monta il motore TRAIN in tutti i suoi tipi
Cercansi Agenti Regionali per le zone ancora libere
LANDI & C. - Via dei Mille, 32 - TORINO"
(...the oldest company using the TRAIN engine in all its types
Cercansi Regional Agents for the still-free areas)
The company may have been originally named Fabbrica Bicyclette & Motore Landi, and may have built their own engines.
Sources: MC Storico Conti, Tragatsch p190, wikipedia.nl.