OK folks...I have tried making the oval key chains using several different fonts with some success simply by doing exactly as you stated.
I use "PageMaker" v. 6.5 and make my outline shape, oval, square, rectangle, and I've even tried a freeform curve.
Then I set the type outside the shape, size it to fit and then move it into the outline.
Just yesterday I had to make a 'masculine' model so I simply took a rectangle with slightly rounded corners and placed large 'block' letters inside. Fortunately the name was "TIM" so I had no closed loops to worry about. Cut out of 1/2" oak and stained a 'dark walnut' to match the interior of his car.
It was a birthday gift and he received it this evening and the lady I did it for said he was very happy and appreciative.
So, no mystery, just 'do it yourself' design! I would guess you all could do the same using InkScape, Gimp, or any other design/layout software.