The original punk movement was in the mid-60's, not the mid to late 70's. The term protopunk, as it is currently used, is a false and misleading (proto-punk was pre 1963). Please see my thread below and my other threads in the talk sections of Wiki articles, "Punk Rock," and "Garage Rock."  In a response to another thread I make a contention that you may find interesting: that punk came before heavy metal (see "Garage Rock" talk).