I managed to get the bus home. Not so fun severely behind on sleep. Anyhoo, basically turned out well. The bus itself was indeed a 40′, 15 window bus. The MT643 transmission was freshly rebuilt in 2009. The engine is a mechanical DT466, 1997 manufacture.
I’ve yet to properly take a look at the engine, but it does have some issues that made themselves known. Only had 133k miles on it, so I’m hoping it is an o‑ring or headgasket that needs replacement rather than a rebuild kit to get it back up to 100%. Runs well enough to drive on for time being at least, though I have no intention of driving it until all’s well. We’ll see how it goes, worst case I’m looking at $1100 so not too bad.
The bus itself is in EXCELLENT condition. So far not a bit of rust or damage to be found. The plywood floor has apparently suffered dry rot (or something), but the metal underneath it is pristine which is all that mattered to me.
All in all, I am extremely satisfied with the purchase and I highly recommend you send Lanny Ashcraft an email detailing the type of bus you’re looking for if you’re having trouble finding it. Or even if you’re just looking for a better price.