That model year is a mechanical engine and will not have some of the controls found on an engine with computerized engine controls so smoke is not unexpected under certain conditions. On a cold start with cool ambient temps white smoke indicating unburned fuel will be noticed for a short time after start up. It should clear up as the engine gets some heat.
When warm and you have to accellerate rapidly you can expect to see a puff of black smoke as fuel is added and the turbo is trying to spool up to provide more boost (air).
You need to have an expert, such as a Detroit 2 stroke engine mechanic check the engine if you question its performance. If you want to learn more about 2 stroke Detroit Diesel engines participate on forums almost exclusively made up of 2 stroke diesel owners such as http://www.busgreasemonkey.com/index.php?p=/
If this is your first coach, proceed with caution. There is so much to learn and enthusiasm relating to coach ownership can get you into expensive trouble real fast. Do not hesitate to ask a lot of questions.
For the moment the dash is going to be the least of your worries, but if it needs to be rebuilt or replaced you should be hearing the loud clanging of alarms going off in your head.
Welcome aboard.