Congratulations, it's been a long haul to find your car, but I'm sure it will be worth it in the end.
It's fairly easy albeit expensive to obtain rear tires in the Pirelli 345/35-15, however fronts (used to be everyone was using Yokahama with a similar tread pattern to the Pirelli) in 285/40-17 are virtually unobtanium. You may find someone who has an old set stashed away but that's a roll of the dice.
The only matching set options I know of currently are the Michelin TB5 (partial tread dry, harder compound) or TB15 (full tread wet, softer compound).
Some have resorted to using race slicks with hand cut treads.
Julian
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