One would not think that it would be that difficult to locate a British coachbuilder with a name beginning with "H", and having a total of five letters. Well it isn't proving out that way. After multiple hours of searching, I came across only one possibility, and not a very good one at that (the founder died in the 19th century!). In desperation I'll say: 1926 Armstrong Siddeley 14hp with a body by Hines.