your request for a cross section build of the Ontario has been noted and it is on the to do list of the SOS/MSB design team.
The design team is made up guys to do kit and project design either for a group or one off projects. We also work with laser cutters and 3D printers. Because it take a lot of time and effort we do not do in depth research. This brings up the Ontario cross section project.
in the book Legend of the Lake 22 gun brig ONTARIO a set of plans were drawn by John McKay. These plans were drawn to the standard ship building methods used in England at naval shipyards. Keep in mind the ONTARIO was built in 1780 in the wilderness of the Great Lakes with limited supplies, carpenters and at a make shift shipyard. Building the ONTARIO to the standards of craftsmanship used in English yards may be questionable.
go here and read the three part article
http://www.navyboardmodels.com/msbj_index_toc
part 1 Dec. 2013 issue
part 2 Jan 2014 issue
part 3 May 2014 issue
the ONTARIO could have been built the way McKay drew his plans or it could have been built with double frames. Size and spacing of frames is a guess. The only way to know for sure how the ONTARIO was framed is for someone to go down and look at the wreck and document the nail pattern in the planking. The odds of that happening is slim to none, for one reason the wreck is being covered with Zebra Mussel.
it is your call as to how you want the cross section designed
some builders are concerned about historical accuracy while someone else is more concerned with the "art" of the model.
historical accuracy in this case is a fluid thing what is true today may be proven otherwise as new research uncovers more facts.
another thing to consider is at what point is being cross sectioned. Most every cross section model is at midship but maybe from the stern to the last couple gun ports may be interesting because you can do the inside of the stern cabin.