The lack of Google results for this kind of construction (relative to the number for the equivalent [i-adjective] + そうだと思う and [i-adjective] + そうだと思った for many i-adjectives) made me antsy about using it.
E.g. 「ジム・モリソンはすごく面白そうだったと思う」"I think Jim Morrison seems like he was really interesting."
Am I doing something wrong here?