What should I do with this liner?

[GTVeloce]

I have just pulled the head off a TS motor with a blown head gasket. Car was running well beforehand. The head is in fairly good shape with a little corrosion around the head studs but otherwise fine.

I then inspected the liners and have noticed a little pitting and am unsure what to do. Is this a forget-about-it or a bit more serious? The engine is just a street motor.

I haven't touched the pistons yet so please excuse how grubby they are.

[Duk]

That looks pretty ugly. 

Take the piston out of it, give it a good clean and run a hone in the bore to see if it cleans up easily enough.
If it does and you haven't had to take too much metal out to clean it up, then chuck some new rings on the pistons (hone the other bores too  ) and put it back together.
Otherwise, you'll need to get another liner.