We used a Sony 355 tape deck.  I wired two Sony MX-6s mic mixers together so we had more inputs.  We had two mics.  We borrowed an extra tape deck,  additional mics and headphones.  The two mixers went into the 355 deck through the mic inputs and  the extra tape deck went into the mixers along with the mic.  We recorded the music on the borrowed deck using several mics and then  played the tape back to Don wearing headphones.   He laid down the vocals while listening to the music tracks, all being recorded on the Sony 355.  I think some of Steve's leads were also done this way.   We used lots of adapters, some I made and some we bought.