I hadnt either until 2 weeks ago, i was a little worried about removing it all but it really was easy.
Personaly i`d say replace them all while there out, chances are they havent been replaced since she came out of the factory, so its not going to harm putting some new`uns in! but thats up to you.
I fitted a Phenolic Insulator Gasket while my mani was off, saved removing it at a later date.