Hi Ciao, I agree with John in his response above.
If you did not add oil and the garage is reporting an overfill, then the most likely source is coolant into the sump, which cranking over the engine will simply have circulated said coolant around the oilways, not a good outcome.
The report does contradict itself of course, in the beginning the oil level is above maximum (substantially) and it concludes that the oil level is way below the minimum mark. Which is it?
Irrespective of the oil levels, the compression test is saying that the cylinders are beyond saving. If you have access to a suitable inspection bore camera, it would be interesting to have a look inside the cylinders reading "0 PSI" (zero) as that would tend to suggest there are holes in the pistons and not merely damaged rings.
The slow cranking even under boost conditions would also indicate that the engine seized ahead of failing - what were the symptoms the last time the car was driving properly? What caused you to take the car in for investigation.
A new engine, well second-hand, should not cost the earth but labour will be substantial. It probably depends what value you think is in the car and how long you intend to keep the car in your possession.
N6 JMX