Contractually, unless there is specific language, I don’t believe so. The contractor may be legally obligated to provide such information to the AHJ during the permitting process, and that information may be available to you through the AHJ’s office.
If you’re checking into whether the proper size equipment was provided and installed, who’s numbers would you want to use? The contractor’s (possibly flawed) calc? Or one you did yourself? In any event, doesn’t the installing contractor’s original proposal or estimate to the owner list tonnages, BTU’s of heating capacity, and/or model numbers of the original proposed equipment?
I don’t believe in “going rate”, but if there is such a thing for a manual J, it seems about a buck per conditioned 10 square foot is pretty typical. (ie, 250 bucks for 2500 conditioned square feet)