Buscema cover inks and Romita alterations confirmed through original art, as seen here (both original by Buscema and original with overlays by Romita) :
http://www.comicartfans.com/GalleryPiece.asp?Piece=882377&GSub=53929
Electro's costume design is a variation of the classic green and yellow version. Most notably, Colan drew four "lightning bolts" extending from the side of the mask, two on each side.