I don't have information regarding the jet sizes, but have some other info that may be of benefit to you.
When I bought my D1200SE three years ago, with 828 miles on it, I immediately made changes at the dealer, so I can not make a comparison to stock.
I had the dealer install a Stage 1 K&N jet kit (K&N was selling the Dynojet kit under the K&N name at the time, and have since then exited that business), a K&N air filter and had the baffels removed in the stock mufflers and replaced with fiberglass. I can say that she has a lot of power, but can't compare to stock.
Below I post the web site for some D1200 goodies. Besides the jet kit, you might also consider the ignition advance plates. I think these give 4 degrees change to the stock advance. Louis, from the Netherlands, obviously feels that the plates provide more power. However, I think that they also slightly reduce gas mileage, if that is a consideration. I have not tried these plates myself and would like to have your opinion in a future post if you make this addition.
http://www.factorypro.com/prod_pages...iumph1200.html