I feel comparing with #27 is a great suggestion. I bet the Museum is in Utah.
According to Walter, #27 has stock lug and Loewe text over the chamber. By pictures posted by Star and
www.borchardtland.com, the triggers have full s/n. Probably many small parts are fully numbered as well. If that's true, changing numbers on so many parts to 19..... of course, not a problem for a professional and the auction price pays for the work.
Ron mentioned pre-production, early and late models. There is one thing unclear to me -- What's the supposed shape of #19? Since #27 does not match the 1893 patent drawing (because of the stock lug), #19 might not match either.