From the service booklet in the black plastic wallet that also houses
the handbook, that should have been in the car when you bought it.

You purchased the car without the service history?  Very trusting!
I would be extremely suspicious of a garage that said it "lost" the
history.  The history booklet is the property of the car owner and
should be checked after each service to ensure the garage has filled
it in correctly.  If it's missing, my first thought would be that
there was something to hide - like the car had never been serviced!  I
would ask them a few more questions about the servicing - did they do
it themselves, and if so, what about their records?  If they didn't,
who did? If they don't know, where did they get the car to sell, who
was the previous owner, and contact details?  But it's all a bit late
now.....

Can't help there.  I've had both those items on my 98 9-9SE replaced
long ago under warranty, but the only symptom I saw was a little white
smoke from the exhaust for the turbo and a note on the service account
for the DI Module - no symptoms for that at all.  I would have
complained if it hadn't been under warranty.   However, you can get
those symptoms from a bad batch of dirty fuel, or fuel with water in
it.  It might pay to check the state of the fuel tank.