Feedback and Info Needed, Piston Rings Gone ! Options

[GordGT4]

Hi guys. Well after 112k miles the Celica's engine has finally got ill. Piston 2 and 3 are down half on compression. This happened while racing around Knockhill circuit.

There was engine oil all through my hose system. At first I thought it was the turbo seals, but after getting the engine looked at by my uncle ( 40+ years mechanic ) it turns out my piston rings have went.

The car drives fine and sounds the same, so hoping it's nothing to serious.

I will be putting it into my fathers garage to get worked on next month. My uncle reckons it'll need bored out 0.5 mm. Of course he wont know for sure until he gets a good look at it. My uncle has worked on cars worth 100k+ but he's never worked on a Celica.

Questions:

Is the block easy to get to, to take it apart or is it better to get the engine out ?
I've looked into engine parts and it'll cost me around £300-£500 depending on what I go for. Any suggestions ?
What would you do in my situation ?