Hi Joe:
You list your location as "Buxton." Is that Buxton, Maine? If so I'm about a half hour from you.
That's the biggest bent spacing I've ever heard of. Timbers are definitely undersized. All those patches look like a hodge-podge and as you say were likely required b/c of the big spacing and undersized timbers.
Kind of looks like a money pit. Too bad. Must have been built by a farmer rather than a framer/joiner. Perhaps the original owner had a get rich quick scheme...throw up a barn and get haying

???
Might it be possible to build a smaller structure out of the timbers? What do you know about the history of the farm?