Having recently traveled with two Navistar Monaco's I was not very impressed... rear radiators and marginal power compared to my heavy Dynasty. The trailing arms where much smaller and closer to the ground. Did not care for the V look. The Dynasty owner was having a good case of the "New MH Blues".
For me what made Monaco special is it's solid handling because of the eight outboard airbags. As for obsolete parts for a Roadmaster... the air bags are Firestone and the bushings in the trailing arms are a common item. Everything else is the same as any other DP. That said, there was a recent
post of broken trailing arm supports on a Monaco Dynasty with 130K miles on it.
ASV will fix two items on MH's they did not build next week at a rally in OR and the Monaco 800 # is still active staffed by the same techs that have been there for years.