hello all im new here and need a bit off help

i need a little advice mate on the following

i have just got a fiesta rs turbo and its not running right. Here is the
problem i think it is Its not running tho the engine does run. It suffered
from backpressure and oil went everywhere and I don't know the full damage
The engine runs at high revs, lots of white smoke. Reckon the turbo may have
been damaged but thats what im not sure about and i need some help if i need
2 get a new turbo or get a new engine all together

also i know a escort rst engine fits into the fiesta but how much work would need 2 be done and fully running

cheers john rae