I have bought one of every manual that I can find that pertains to my '35. I have a '35 specific, '34-'36, '36-'42, '46-'54, '55 specific (it used to have a '55 engine in it), '57 specific (it now has a '57), MOTORS, Clymers, The Complete Handbook on How to Fix Plymouths Illustrated plus a collection of parts manuals.
I have used each one as each one has a little different information. As time went on, the shop manuals seem to have more and more information.