OM Symbol pictorial collections or files

[Stanley Rice]

Dear Indologists,
Does anyone know of a collection (book, files, visual references, etc)
of classic or modern OM symbols? Hinduism Today has a small collection
on their web page, but reproductions of historical symbols seem hard
to come by. Any references will be appreciated, especially if from
available sources.  
Thanks, Stan Rice

-- 
Stan Rice, Autospec Inc, srice at cruzio.com