http://www.postwarlionel.com/cgi-bin/postwar?ITEM=617
History
The 617 A.T. & S.F. NW2 diesel switcher was produced for only a single year; 1963. Quite surprisingly, Lionel actually added external detail to this switcher, something that was rarely done during the 1960's. For the 617, Lionel added a radio antenna on top of the diesel cab, a piece of trim last used in 1955.1963 also marked the year Lionel began transitioning their switchers to a less-costly, sheet-metal frame which did not include side skirts. As a result, the 617 can be found with either the early frame containing side skirts or the later version without the additional side detail.
Although NW2 switchers produced in the 1960s are generally a step down in quality to those produced in the 1950s, the 617 does contain several of the more desirable features such as two-axle magnetraction, functional horn and much more.
The 617 is a fairly rare diesel. It was only produced for a single year and those in collectable condition will command a premium in price.
Features
Standard features of the 617 include: black painted body with white lettering and strips, two axle Magnetraction, three-position E-unit (with the lever accessible from underneath the frame), functional horn, single illuminated headlight and non-operating couplers on the front and rears. Additionally, the 627 is the only NW-2 switcher produced in the 1960's with a simulated radio antenna on the front of the diesel.As mentioned above, 1963 was the year Lionel transitioned their switchers to a less-costly sheet-metal frame. The change eliminated the simulated side skirts on the diesel. Locating any 617 is rare, either with or without the side skirts.
And here is one in the wild, suffering from dry bearings and a bad horn:
The chassis is notable for the C-cell powered horn and the more economical (and fragile) L-19 light bulb.
The commutator and bearings were in perfect nick, and just needed a light cleaning and oiling, with a bit of grease on the worm gear:
The horn, alas, was a different story:
While everything is clean and shiny, the coil has given up the ghost, so another horn will have to be installed in future.
The front coupler had a cracked centering pin:
So, I swapped couplers with a 627 center cab on the dead track, upgrading to working couplers at the same time:
Note the black rubber hairband on the coupler. This increases tension on the pin, allowing for remote operation while lessening the likelihood of it opening at an unwanted time. Also note the temporary grain of wheat bulb, until I can order some L-19s from Train Tender. 
Here's the 617 back in action, pulling the future Crimson Comet consist with nary a bobble!
Mitch
