To answer your question...yes...the Aristo RDC has been 'selectively compressed'...
I assume to handle curves, switches etc, but still contains the essential elements of the original such as number of windows and the proper placement of the roof exhaust etc. I think they are an excellent diesel.
I am an RDC fan and according to a review in GR magazine a couple of years ago, the Aristo RDC-1 measures 31 3/4" long; 4 1/8" wide; 6 1/2" wide. I wrote these figures down because I wanted to build a shelf to hold mine when I bought it.
This works out to 76'-9"long x 10'wide and 15' 8-1/2" high in proto size or about 8 feet shorter than the real thing.
The prototypes were 85 ft in length as they were patterned after Budd's stainless steel passenger cars. There were RDC 1, 2 3,4, 9 (or 5) various configurations made... all 85ft except the RDC 4 which was built for RPO use and was only 72 ft long.
Aristo is coming out with an RDC-3 soon which was the half baggage, half passenger model.
Also the 1 to 1 cars were 14ft 7 inches high top of rail head to the exhaust stack. I have two of the RDCs now and really like them will be getting the RDC 3 when they arrive. Make for a nice 3 car set. Later RJD