Jonathon Hayt of Tucson, Arizona, supplied very useful information on sidecar manufacturers. emnjonh<at>comcast.net
Paul Markham of Australia and Eugene Smith of Arkansas supplied manuals for Heinkel, Durkopp, Progress and others.
From Australia, several images of KTM, Vespa and others from Byron Bay Motorcycles
Immagina by Gyp of cyberium.net supplied numerous quality illustrations. (1)
Marius Pfister of Oldtimer Werkstatt, restorer of all manner of motorcycles, cars and antiques.
Rick Zolla, Montanaman
Roger Henderson, CZ/Jawa
Nathan Dodge scanned over a hundred pre-digital photos of classic bikes from various museums he made over a period of 20 years.
Mike Christopher (Ariel, Omega, P&P)
Todd Koehn of Antigo, WI (BMW R100S)
Hans Smid. Information from his motorcycle archive at hanssmid.nl
Ton-up-Boys Australia supplied wonderful photos by the late Dave Morgan
Robert Livingstone, Puma Archive supplied a considerable amount of information on motorcycles built in Argentina.
Pekka Puoskari, a keen collector and restorer from Finland.
A number of quite fine photographs supplied by Gravitat-OFF
Rene has taken photographs of European museums: Rene at Flikr
Kotomi supplied photos from Brooklands Museum: Kotomi at Flikr
Thanks to Doug Lyon for images made at the Glasgow Riverside Museum.
Apologies to those not yet mentioned.
Many more not specifically mentioned here are referenced on pages devoted to museums and collections, nationalities and professionals.
1. Site offline