On the 1975 1150 I'm restoring for my GT 160 this decal was still in place, I've never seen one. It's made of paper so I'm sure they get removed or disintegrate almost immediately. It's near the electrical side plug.
If anyone is interested I asked nymarine to remake it as well as the "lift for cold start" decal seen on the Merc choke lever. This had a good one of those so I took a pic of and sent it to them to remake.