Old Engine is an area in the Forest,near Steam Mills north of Cinderford

Old Coal mine called Old Engine Colliery near Bennett's Mill - this mill was a steam powered corn mill, which is thought to be why the area is now known as Steam Mills...

In 1856 the Beerhouse was called Old Engine after the colliery . by 1878 the Old Engine Inn was in new premises as the Newtown of Steam Mills developed.

http://www.old-maps.co.uk/
364901,215700

< and you will find the Old Engine Brook and Inn there as well>