Fair comment about being in a rush.
Hmmm a pity that you have more problems to contend with. Dieseltech has covered most of the potential damage that could have occurred.
Have you removed the engine oil dipstick when the engine is running? A small air/oil spray is not uncommon but if there is a specific blow of air and oil drops coming out that would confirm that compression is passing the piston rings.
Has the thermostat change cured the overheating problem? I assume that North American 165 radiator necks are the same as ours in the UK. It is not easy to look down them to see the end of the tubes and if there might be any blockage. This of course only allows a very small area to be seen. Have you used any radiator flushing product? Is there free passage of air through the rad fins. Is your water pump and fan belt OK?.
The '203 engine is almost bombproof but like everything else has a limit.