I believe Reagan praised Paul’s accomplishments fighting for a stronger national defense in 1978, and Paul criticized Reagan for deficits in 1987.
I just tracked down some details on the Reagan quote. He apparently made that endorsement during Paul’s 1978 congressional campaign because Paul’s rivals in the Republican primary were attacking his noninterventionist foreign policy and trying to paint him as weak on defense.
http://www.theatlantic.com/politics/archive/2011/02/when-ronald-reagan-endorsed-ron-paul/70913/