Vern:
First, thank you very much for your suggestions, your recommendation about practice preceding regulation, and also for your caution about narrowing (I'm trying to narrow, I swear). .
Second--the development of the UCF itself is my focus right now, so I very much appreciate your reference to that specific Federal Register cite. (I'm not just interested in its historical development, though--I've interested in how it functions as a sort of heuristic device (or cognitive module) within the contract document itself, and for various audiences).
When I look more at the boilerplate language, I think I'm going to be looking at construction clauses. The changes clause(s) are definitely ones I've been considering.
I'm not horribly far from D.C. and am hoping to get a chance to do some archival research this summer.
Again, thank you.