Cat 920 that has been sitting

I am purchasing a '78 Cat 920 loader that has been sitting for 7-8 years. Its a 62K 9xxx serial number. It has a 3304PC engine in it. It comes with the famous story of "ran good when parked". The engine is now seized up. I'm sure there are no miracle cures, and it should just be bought with the thinking of doing an out of frame rebuild? Is this the approach you would take? Any insight is appreciated. Thanks.

Cat 920 that has been sitting