I flew to Bern in Switzerland last Sept. It avoids having to go over the really high mountains, so shouldn't be a problem in a C150.
For some really nice scenery we got a hire car, and stayed in the
Eiger Hotel in Murren. You can't get up to Murren with a car, so you have to park at the 'base' of the mountain, get a cable car up, and then a train along the side of the mountain.
The views are fantastic, and the hotel quite nice. There is plenty to do and see within a 1-2 hour drive of Murren, to keep you busy for a few days....a lot longer if you enjoy hiking.
It's a pretty simple trip to make.
Some pics of Murren.
I seem to remember parking being about €30 per day day, and landing something similar.
dp