Factory Chrome 16" wheel question

I have a 97 EB with the 16" factory chrome wheels. One of the center caps went flying off yesterday. I noticed that it wont stay on because the chrome "wheelskin" is seperating from the steel wheel. Does anybody know how these skins are actually attached to the wheel? Has this happened to anybody else?
thanks in advance

 

[eddiebauer97]

bump

 

[BigAlain]

Same thing happening to my `05 rims...