system to be in small area, less than 60sq feet. Want to use existing
100w amp with 2  "large" speakers,vintage 1970 tech details unknown.

To the best of my knowledge the only thing you can eliminate the wire
from is the audio source.  The existing wireless speaker systems use
short range RF to broadcast and a built in RF receiver in the speakers
to receive the broadcast and send the signal to a built in amplifier
all within the speaker itself, requiring batteries in the speakers or
for them to be plugged into a wall socket.
No matter what you do you are going to need the speaker wired up to
the amplifier to deliver the current needed to push the speakers.  You
cannot wirelessly transmit current outside of static electricity.  The
ability to transmit actual power through the air isn?t around yet.
So you can separate your speakers from the source of the audio but not
from their amplifier.  Also the speakers with built in battery powered
amps are generally horrible and incredibly underpowered as they are
powered by a couple batteries.  Sorry

Just as an example here is what to expect from the average wireless speaker,

 8 C batteries or plug it into a wall.
http://www.smarthome.com/8243-10w.html
http://www.smarthome.com/8235.html

Rechargeable, with a 3.5 hour life between charges.
http://www.smarthome.com/8214.html


Or you can put these between your audio output and your amplifier.
http://www.smarthome.com/76540.html

Oh and I had someone at work just tell me that we can send Current
through the air but its rather unsafe.  Tesla coils.