Turabian's "A Manual For Writers of Research Papers, Theses, and 
Dissertations, 7th ed." supports the style below of placing the 
original year of publication in parentheses.  See standard 19.1.4, 
page 238: the reference page listing would be:

Keynes, John Maynard. (1936) 1964. The General Theory of Employment, 
Interest, and Money. San Diego: Harcourt Brace & Company.

And the inline citation would read:

(Keynes (1936) 1964, pp)

Not to say that a particular manual of style ought to be adopted 
(although that would not hurt), but there is precedent for listing 
the original publication date of a reprint edition when it is 
important to the context of one's paper.

Doug Meador