Help! Newly renovated engine got stuck while cranking it...

You could confirm that by putting a little oil in the cyls and a quick shot of air to blow it around in the cylinders, then try to turn it backwards first then forward again. (Real easy just to move the rings a little)
If it free's up then do a comp test and see what you have.

Even if it does free up cudascott's suggestion is a really good idea, just to see how marred the cyl walls are.