This one was submitted by my good friend Tim Dannels. It's a fairly close copy of a mid-1950's Allen-Mercury (A-M) diesel with the four columns at the base of the cooling jacket. However, unlike the original A-M engines from England, it bears no marks of identification whatsoever. Tim hasn't measured it, so he's unsure whether it's a .15 cuin. (2.5 cc) or .21 cuin. (3.5 cc) unit. It's one or the other.
We initially thought that it might be an early product of the Aurora company from Calcutta, India. However, Aurora confirmed that they didn't make this engine. They suggested that we try their fellow Indian manufacturers, the Sharma company from Jodhpur. We did so, but drew a blank there as well.
IDENTIFICATION MADE!! The engine has now been identified by both Kevin Richards and Ian Russell as a product of the French M.S. company. It was a pretty close clone of the A-M models and was produced in both diesel and glow-plug forms. The 1 cc M.S. 10 appears on page 96 of the book "Les Moteurs Modelés réduits Francais” (French Model Engines), compiled and edited by Adrien Maeght. Thanks, guys!!