Actually I have an 8 car set of the Bachmann in the Acela phase 5 paint with the Blue stripe and small Acela logo as you see today, that seems to be the only correct paint job Bachmann did on these cars. Having both the walthers and Bachmanns I can say that the paint jobs on the Bachmann or worse then Walthers for Phase 2,3,4, and older Acela with the bubbles on the cars, all the lettering looks way to big on the Bachmanns requiring stripping and repainting them.
As for accuracy of the cars the Bachmann cars are more accurate then the Walthers as far as the car cross section goes. I am also planning to model the Lake Shore boston section but from the earlier Phase 3 days when the F40PH's were still used along with the new P40's as I have many pics of the train in Springfield, MA when they were doing Roadrailers there.
As for the diphragms I painted the smaller part black leaving the striker plate silver on the end and the inside silver as well. I also body mounted Kadee couplers moving them in a little to have the diaphragms touch each other all the time with no gap.
If you want to model todays lake shore then all you actually need is a Walthers 1700 series baggage car, 2 coaches, and 1 Cafe. At least thats what I see most of the time lately.