Re: 1977 6 HP Johnson Engine Cowl needed
They show up pretty frequently on ebay. You could also find one at an outboard wrecking yard, like
www.tcoutboard.com.
You might even try some local outboard shops. They may have one from a junked engine.
Finally, I think there are probably several years around your model that will fit. That engine was around for a long time, and they probably didn't change the physical dimensions all that often.