Carol - I have seen one - Loretta stitched a great FSL one a while back - she had it in projects. It was free, too but didn't have the 21 on it - but think is was big enough to include that.
How about I digitize one for you? I can take a photo of my husbsand's 21st birthday key and change it a bit.It was made for him by his friends when he was still going to sem.
Have you still got my e-mail address?
Found an old key here: http://www.digital-stitches.com/f... but it doesn't have a 21 on it. Maybe it will help.