Todd, the dimensions are identical to those plows used on both the K-36 and K-37 classes. The only difference was that they had to cut out part of the top for clearance of the air pumps.
If you need rough dimensions, but pretty dang close, write me backchannel and I will take measurements from one of my models.
I've said this before, and I'll say it again, approach drawings from the Maxwell collection, and other collections, by the way, with at least a grain of salt. Some of Maxwell's plans are drawn from actual D&RGW plans and drawings, others are useful for field dimensions, but have fanciful Dr. Suess-like roof pitches, and some of them are completely inaccurate. It's always good to glean information from all sources you can, and the Maxwell collection is a valuable source, you just have to be careful about having blind confidence in them. I've used Maxwell as a source on several projects over the years, and will use him again, you just need to go into it with your eyes open.
Mike