The easy route I took was using ClassicParts (years ago they were Chevy Duty but were forced to change their name legally for using "chevy")
This lock set is only $40
http://www.classicparts.com/1967-72-.../#.WPTOKIjyuUk
I will add, i usually HATE getting email ads from companies, but they often send me 10% off order emails around holidays, in case you are in to those email flyers theirs are actually worth getting...
LMC has never been able to compete with their prices (on anything I have bought)
LMC has a great parts catalog and exploded views, but they charge more than other companies might...