Testarossa problem "Slow Down Cyl 7-12" light.

Most likely you've lost a bank of ignition (and the "slow down" system is working correctly). Also shows why having some goodwill with the Shop that did your expensive major service a short time/mileage ago is far better than having no relationship with the Shop that the Seller used for the major service before selling . I wouldn't worry too much about a small amount of gunk in the engine oil filler tube on the oil tank (especially on a TR only driven 500 Km in 6 months).

 

That's because all of the "overheating" is occurring inside the exhaust system = the coolant temp stays normalish, but the radiant heat transfer from the red-hot-glowing exhaust components heat up everything exposed to it -- worst case, things catch on fire. (Radiant heat transfer is the same way that energy gets from the Sun to the Earth thru the vacuum of space -- it's not our everyday experience of convective heat transfer.)

 

Yes, losing a bank of ignition spark -- the air-fuel mixture that should be ignited inside the cylinders doesn't get ignited there, and, instead, gets ignited inside the catalytic structures. Easily confirmed/denied if a bank has lost ignition spark by using a timing light or a spark tester. Many possible causes -- oil inside the dist cap, broken dist rotor/carbon button, bad coil, coil wire fell out, bad ignition power module (this is probably the most common cause), etc..

Any TR with "slow down" lights has cat(s).