iboats has parts lists back through 1968. Many, but not all parts are same as your '64. Click "Parts" at the top of this page, then the OEM icon, then follow through with make and model etc. A '68 would be Model 6802.
iboats also sells aftermarket service manuals, not bad for a novice in spite of the negative publicity. No one book is going to make an outboard technician out of you. We had to go to school for that, along with years of OJT.