need original 1978 cb750F muffler/exhaust

[bluefisher1]

 Hey folks, just joined this forum. I have been doing old wings but have always wanted one of these and there she was waiting for me. I would like to keep original with only upgrades to the ignition and brakes. I am looking for an original exhaust muffler to this bike. So, if there is one out there I would appreciate a shout. Now I will try to post a pic.. 9800 miles, she is sweet! thanks in advance.