Question about a trade

In the end, yes. Even if the 440/413 don't run. And the 727 needs a rebuild. You're still coming out on top. If either engine runs, or the 727 doesn't need going through. You're ahead by a mile. You'll never do anything with a 7-1/4 rear end. Ever. Honestly. You probably couldn't buy a pulled 440 for less than 500. So yeah, it's a good deal.

If it was me?

Build the 440
Build the 727
Turn the 413 into a beer/wine holder that dispenses bottles as you turn the crank. Maybe a Coffee table. Or something else neat.