Re: Turning Engin
Welcome to this forum. Assuming that when you put the engine together it turned freely and the crank bearings were assembled well lubricated then it's most likely the piston rings rusted in the bores. You can try taking out the spark plugs and spray some WD40 or paraffin into the cylinders and leave it to soak for a few hours.
Before refitting the spark plugs you can gently try turning it over by engaging a gear and rocking the car backwards and forwards or the with a socket on the front pully nut.
If it frees up you should then squirt some engine oil into the cylinders to lubricate the pistons and rings. When you are happy that it has freed up you'll need to drain the sump of the WD40 or paraffin and refill with fresh oil.
Before refitting the plugs crank the engine over on the starter to get oil pressure up. You may need to prime the oil pump if pressure does not come up while cranking!
Hope this helps and you don't finish up having to strip down the engine again.
Do let us know how you get on.