Larry,
Six months is unqualified. You should make careful notes about everything thought. The 455 production ended about mid 77. that does not mean that yours is not, but it may have a few things strange. It is very possibly a dealer change or not a real 78. (I have one of these in my back lot.) Its VIN says 78, but parts of it are not.
Whatever, you have a pretty coach there. Have you hooked up with a local chapter yet? Where you are, you are in the territory of both Heritage Cuisers or Great Lakes. Either will welcome you. Great Lakers activity tends to be way west of you. The drive around that bottom of Lake Erie isn't all that bad, we have done it a lot (contact me before you do). Heritage Cruisers are interesting in that it is a chapter defined by a boarder crossing. Many of the members are in Canada. That didn't used to be a problem.
If you are up to a multi-day journey in September, think about getting to the international in Chippewa Fall toward the end of that month. If you get there, be ready to be overloaded with TZE specific information if you stand in one place and listen.
Matt