Not much is known about this English firm. 

Andreas Franz Leale of Soho in London was a professional coppersmith. His works were very close to other manufacturers in London including Siebe, Heinke and Lang. For this reason you will find that helmets of these manufacturers look a lot alike. Manufacturers had a good look at each others features (like they still do today).

Recently a viewer contacted us and said the Leale helmet is in fact a Siebe helmet but Leale took the tag of and put his own name on the corselet. This is not true. Leale introduced his helmet to the public on an exhibition in London on april 15 1882

Leale helmets are VERY rare. The helmet you see in the picture is known to be the second one to surface! It is at least 110 years old. You see that it was modified on several parts over the years. 

Thanks to Dr. John Bevan for his help on this part.