+1 to everything max said.
until you really do a tear down inspection everything is speculation. as things are discovered different plans will have to be made.
for instance, if the bottom end is fine you can get away with a hone and re-ring and some bearings. but say the heads are waxed? do you pour 1K into the factory heads or pivot to something else? what does your budget say? what do you really want out of the build?
say you start poking at it, pull a thread and the whole thing unravels like a sweater. block is fine but the crank is wasted, needs pistons, maybe a rod or two and the heads need a full go thru. do you change direction and buy a reman 318 and dress it up like 273? do you build a mild 360 and do the same?
does having the commando motor in the car make it inherently worth more? is the originality of having the commando motor worth enough to justify the cost of rebuilding it for you?
there are a million subjective questions that need answers and no definitive one answer-- right or wrong.