Parachute question

I'm planning on purchasing a new or used parachute to replace mine that
does not fit the contours of my ship. My question pertains to the
accepted longevity of emergency parachutes which I've often heard is
about 20 years. Because mine is 27 years old, I was just about to toss
my Security 250 in the dump. However, I recently reread an article by
John Good on parachutes published in Soaring (March 2003) which quotes
Ted Strong (of Strong Parachutes) and a colleague as saying, "...there
is no need to impose a limited service life on an emergency parachute."
What's the consensus by others in the sport? Should I try to sell it
or trash it?

Duster