May I humbly point out that the first Legacy offering of PM 1225 from 2008 is missing from the list? Catalog number is 6-11146.
Greg
Good catch! It has been added to the OP.
Dave
Gee, I've never received a 21 gun salute before. Thanks! 
PRRJIM and Marker
Thanks for sharing the information on earlier brass Berkshires. There is very little info on the web regarding what brass models have been manufactured over the years. With info on brass model this can really become the reference source for O scale Berks.
Bob2 also shared some information on another early O scale Berkshire model and he has graciously allowed me to re-post his photos here. One prototype not yet mentioned are the 12 Berkshires built by Alco in 1927 for the Chicago & Northwestern. These were the first Berks built with cast steed trailing trucks and they also served as the pattern for the five IGN/MP and the two TH&B Berks. Lobaugh made a model of the C&NW berks circa 1940. With the lack of a mention of a more recent brass model they may still be the best bet for a fan of the C&NW Berkshires or their derivatives.
This locomotive is stock Lobaugh.
Bob2 modified this Lobaugh model to depict an MP Berk. His dome configuration very accurately models the Mo Pac locomotives.
