What a great comparison!
Looks like mth 20-3760-1 and Lionel 6-85172.
Interestingly mth had in 2017 made a similar model with the lighter paint scheme.
If I identified the models right the Lionel msrp is 1399.99 and the mth is 1099.95. Lionel says its model will do 036 but I am not sure I believe that, and mth says O42.
I would also have to give it to Lionel on the whistle, it sounds like what I remember. The mth unit just looks better to me though.
Both are fantastic.