playing one hole

hello my name is JR Martin i am a new member just joined half an hour ago
started playing two weeks ago
I’m 73 years old. sixty years ago i had a harmonic and i also had a plastic mouth plaice
it was about 1 in wide and it was molded to the face of the harmonica it had one hole in it
you would slide it on to the harmonica it had to be a snug fit put your mouth over it and slide it
to the note you want . blow or draw . if you can read tabs and control breathing
you can play simple songs great for kids if you know anything about it please email me.
THANKS

                                 Jr martin

Welcome to the forum. I’ve never heard about a harmonica like that, but there is a place that may help. It’s a forum called SlideMeister.com. There are folks there that know a lot about the history of harmonica.