So , are you gonna get it freed up? All different ways to do it. Fire method, block and hammer method, concoction method, hang it by the jug method, air hammer on a large socket over a block method, or reinstall the head (no cam) and do the grease gun method on 2 or 3 since they are up.
This motor could be in reasonably good, rebuildable shape and you don't know it.
Get it free ( I would do the greasegun method on this one) low impact immediate results.
tear the whole thing down, split the cases and see what kind of engine you really have there.
If it's yucky and you can't be bothered , it's on you.
If your scared and need a support group, we're here for you.
What's it gonna be?