If you wanted to get rid of the package as boat, motor, trailer, then spring is the time to do it and it does have some value as a package. The 1970's Sea Rays were a well built boat and one of the first of the deep vee boats. As for the Johnson, the V-4's were built starting in the 1950's and well into the 1980's so parts should be available even though OMC went through hard times in 2001. There are a couple places I know that should have the parts for that. If the package is decent, it is worth doing a little work to upgrade it.
I had an 1982 115 Evinrude, for trolling and use like that it may have used 12 gallons per day so it was not that bad.