My older Gen 3 Glock 23C has a black sleeve around the front of the striker assy; obsolete?

[LiveLife]

As long as the striker spring caps insert into the sleeve and alignment of firing pin is maintained to the slot in the breech wall, I would not replace it.

I looked into the role the Firing Pin Channel Liner played to see if loose liner could pose any issue.

At 1:40 minute, video shows role of Firing Pin Channel Liner of aligning the firing pin with the Firing Pin Safety Plunger. I wondered about loose liner affecting drop safety but at 1:55 minute, video shows it is the Firing Pin Spacer Sleeve (inserted over the rear of striker) that holds striker in place for the drop safety.