Changing Liner, question on U channels holding it in place ?

[toyopl]

Need to change liner next year as it's extremely faded, and want to go with Unibead installation so I can simply hook it up top.
Current liner I believe is overlap or Jhook, and then metal U channel to hold it in place, and plastic U channel over metal one for some reason.

Metal u channel is rusted out, it's crumbling.

When going for Unibead/Jhook do I still need to install metal and plastic channels, or it's no longer necessary ?
Checking if I need to buy all new metal channels.

 

[Texas Splash]

This may be a long-shot since he's been away for a while, but I'm going to try and tag @jimmythegreek who is an expert in the field on this subject. Let's see if we get a bite.