I have a I6 I am getting rid of, Im in spokane bring a truck up and Ill help you pull it. its sound and runs damn good.
Wow! I've never seen that happen to a 250! I know it didn't have oiling problems cause the crank journal looks fine! Had this engine had any previous work done? Like was said before, looks like a bolt let loose. I had an MGTD do the same thing! It was running fine and all of a sudden a bang and then God awful, horrible noise! It never quit running either! It was the last cylinder also!!! I would definitely fix your car! It looks really nice and is worth a new engine!
Don't know if it had any work done. My dad also thinks someone must've made a mistake/left something loose on a rebuild for this kind of failure.
Engine replacement in a 6 cyl Maverick is suprisingly easy. Even as a young novice, I had no trouble taking one out. Your car looks very nice tho. Post it for sale before you let that go to a salvage yard. AutoKrafters sells the reproduction service manuals for a reasonable price. I highly recommend just getting a manual and give it a try.
I haven't seen it in person but it's way too nice to die from the pics. Hope the engine works for you.
Definitely going to try to bring it back to life! Interesting that you encouraged me to "try" given your signature