welcome RCB:

What comes to my mind is a 40' building w/ only 4 bents... that's a large spacing of ~13' or more. Perhaps that's why it has such beefy timbers.

Of course, the steeper the roof the better it will handle any snow loads. The code requirements for rafters typically decrease as pitch increases.

Again, that's a large bent span. Perhaps even more of a consideration w/ those softwood timbers. But there's a lot to be said for the test of time.