Harry Partch Information Centre - Error?

Hi there!

Just checking the information at the Harry Partch Information centre

http://www.harrypartch.com/partchworks.htm

The Letter (1943) for intoning voice, kithara, harmonic canon,surrogate kithara,
diamond marimba, bass marimba (There was an earlier version which has been lost)

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This is not very clear to me since did not make the surrogate kithara until 1953 (Genesis of a music p.231)
Harmonic Canon (1945) (Genesis of a music p.235)
etc ....

This doesn't make sense to me and I hope that someone here can clarify the date of the lost early version (I guess that is 1943)
and the date of the version (at least 1953 I guess)

Sincerely

Tony Salinas