We have lived in our 1960s ranch house for 23 years now, and little by little, we have come to appreciate its design integrity. So, first I would recommend that you look at the house more closely. Is it really lacking character, or is it just not your personal style? Are the rooms small? Are the windows ugly? Or is the house just simple in its form and appointments? Houses from the 60s often have long and lean lines which can provide a spacious canvas. In any event, I wouldn't abandon your love of shabby chic, but I would think of it as an accent to a more minimalist approach. For example, on a simply lined couch, you could use throw pillows made from a shabby chic fabric you adore. You could then pick up some of the colors in those pillows in some vases that are more authentic to the house's era. I think if you don't overdo it, you can definitely incorporate some of the design that makes you feel good but still have it reflect the house's era. You don't really indicate how much you will be doing to the house. Are you renovating, replacing windows, adding on, etc. or just decorating?