Unfortunately, there is no part number for the plastic clip by itself.
The clip and all other small parts are only available as part of the complete hydraulic line assembly, hence why it's strongly advised to only use the hydraulic line disconnect tool to wriggle it off, and not something like a screwdriver or knife.
You might be able to get someone to pop the clip off a vehicle they are parting out, or from someone who replaced the hydraulic line.
Some people have also had luck getting a custom hydraulic line made, with braided hydraulic hose in the middle and matching ends, so you might be able to go that route if a shop that makes hydraulic hoses can get the ends. The clip on the new aftermarket end probably won't fit onto the factory hydraulic line, but it might.
