Unrelated to gyros but years ago my A&P recommended I change all rubber components .... Lord Mounts , Dynafocal mounts , rubber tubes and hoses etc.
He quoted the mfg price for the kit and it shocked me .... too much money for a handful of components. I continued my grumbling at lunch and a friend knew somebody who had the exact kit for half the price so I sent the cash and got the parts.
Couple months later I was due for 100hr insp , brought the new rubber parts and asked my A&P to change them ... he dug out the packaging and showed me the mfg date was actually older than what was currently on my aircraft.
It cost me 1 & 1/2 times as much to learn an expensive lesson. Turns out that manufacturers of rubber components , elasomeric bearings etc only make small batches at a time in order to always have fresh stock. If those components were not calendar sensitive they would mass produce millions of them at low cost and warehouse them until sold