There is very little information available from searching, to definitively nail down exactly what motor was used. There is a 289E listed by JDPLTD, and one photo shows the E unit is visible looking into the cab, which shows the lever is bent backwards at a 90 degree angle. The body of a 289E doesn't have an open slot for a lever from the E unit. The wheels on all of the photos I have looked at are 12 spoke counter-weighted wheels, which would make them 1937 issue.
Dewassociates has wheel sets (two different ones) available, and the one set indicates they were used on a 249E, and few other motors, which is what it probably came from. Lionel made a decision to make a lower priced 'Commodore Vanderbilt' with the smaller 027 sized shell, basically using a 1689 body, and cramming in an "0" gauge motor. As you mentioned, the 289E was made in low numbers, and the standard tender that went with it was a 1588T. There will be conflicting information, referenced from Dave McEntarfer's books, that will state that it came with other tenders, but the normal was the 1588T. The 289E ONLY came in sets, and never sold separately. Take it for what it is worth as far as info, as I have no personal knowledge of the 289, nor do I own one.