I have 2 ea71 seized motors I managed to get the Gudgeons out of 3 of the pistons in one motor, the 4th piston and  Gudgeon are truely seized. 

The second motor the pistons wont even move, ive been tempted to force then with a big hammer and piece of timber in an effort  to remove

the Gudgeons and split the motor to salvage a few parts only other option I guess they will end up at the scrap metal yard.

Also posted on one of the FB groups, yes? 

You’re in Australia? Has the EA71 gotten that scarce down there?
 

I’d move on just thinking the internals are not going to offer enough vs the effort. And that there’s another engine or two to be had cheap enough. 
 

If you’re hell bent then I’m only likely to offer the same advice of others. Soak , heat , soak , heat , effort. Good luck.

 

Stay healthy during the process!

You could try using some rust buster in the bores - this might free up the engine once all cylinders are done. 

Hammerbarn stocks the product of that name. It’s good stuff! 

Cheers 

Bennie