I dont know if there are any crossover models between the UP, ATSF or DRGW and Frisco as far a Brass goes but we have for sale here in GJ a rather large collection of UP, ATSF, DRGW brass. There is some Narrow gauge stuff for you "narrow minded" guys.
Prices are descent too. This guy is just selling an Estates brass collection, maybe 50-60 pieces.
Email me if you want a list.