The Hope "B" .29 cuin. model was the first product of the Hope Engineering Company of Tokyo, Japan. It appears to be closely related to the early post-war Kotobuki engines which were made in small numbers by Tekkosho Sato, who was reportedly involved with the subsequent establishment of the Hope range.
The Hope "B" appeared in 1947 as a spark ignition motor. Although built to a rather minimalist design and displaying little concern with "eye appeal", the engine was very well made indeed where it counted, hence being an excellent performer with good durability.
In late 1948 the Hope "B" was reconfigured as a glow-plug model, in which form it ran very well indeed, as present-day tests have confirmed. It survived in that form until late 1949 or perhaps early 1950, when it was replaced by the first of a series of new loop-scavenged Hope 29 models.
Full details of the Hope "B" and other Hope models may be found in my earlier multi-chapter article on the Hope range which appears on Ron Chernich's "Model Engine News" (MEN) web-site.