The Mixte on ebay has a very distinctive "H" built in the dual down tube/seat tube lugwork.
http://ebay.com/
The classicrendezvous and classiclightweights web sites
http://www.classicrendezvous.com/
have a long list of builders with H in their name.
Pat Hanlon Reg Harris R.O. Harrison Jack Hearne Cycles Hetchins Hercules Hill Special Hilton Wrigley Hines of Finchley Hobbs of Barbican Holdsworth W. B. Hurlow
Has anyone a clue who this H belongs to?
Amir Avitzur
R"G Israel