Going on memory here:
Committee of Safety muskets were ordered at the beginning of hostilities. At that time the British Land Pattern was the model that most folks in the colonies were familiar with, and the specs given for the gunsmiths to follow reflected that.
After the French sent us a bunch of slightly-used 1763s and 1766s, which were almost state-of-the-art at the time, the CoS muskets were no longer manufactured and were essentially second-line weapons (I don't know if they were actually withdrawn from service, though).
French muskets, being both plentiful and the most advanced weapon available to us, remained the standard issue weapon until we started manufacturing our own, somewhat ersatz, copy in '95.
As for American parts-built muskets in general, there are numerous examples with reused French parts. I believe that most of those parts are off of pre-1763 models, though, which suggests to me that the government hung onto the 1763/66 parts to repair its inventory, and the civilian-made guns are made with older parts that were already floating around prior to and during the Revolution or that were surplused off during or after the war.
There is also at least one musket made from Brown Bess parts but stocked and altered to look like a 1763 French musket. Very interesting...