Hi Arnold,
Yes, those are Railking sized PAs. Alco PAs were intended as fast passenger locomotives. This was their use for their first decade on the New Haven (1948 - 58 or so), where they typically ran New Haven - Boston and New Haven - Springfield. After the arrival of the second set of FL9s in 1960, and the reduction in passenger service across the New Haven, many were used as single units on secondary passenger trains (i.e. Boston-Providence local service) or reassigned to freight use. The NHRHTA had a great article on them a few years ago, including several photos of 4 MU'd together hauling freight on the Maybrook line.
As Rusty noted, the paint scheme your models are wearing is called the 'Alpert' scheme, after George Alpert, who took over the railroad after Patrick McGinnis left in 1956 until bankruptcy in 1961. The scheme was adopted ~1960, as a cost cutting measure. The Alpert scheme was cheaper to apply and easier to keep clean than the McGinnis scheme by eliminating all the large white areas. This would be the fifth and last paint scheme applied to the PAs - the others being (1) hunter green and warm orange with silver pinstripes, (2) pullman green and gold stripes, (3) original McGinnis scheme (white band on bottom), and (4) reverse McGinnis scheme (red band on bottom).
~Chris