Peter, you are correct. The TC-505 was an earlier model resembling the 222, 555, 777 , 999 amps and corresponding tuners; and the original CD-5 active crossover (not the CD-5A).
I have to say I have really come to admire the look of the series built around the 606, 150 and related models. Tastefully understated yet modern enough to look a little less industrial like the 222, 555, 777, 999 lineup that preceded it. If the latter still looked very 1960's (not that I'm disparaging that look, it just isn't to my own taste) the follow up series was a bit cleaner and more streamlined.
I think the thing I dislike most about the look of earlier models like the 777 and 999 are the clunky black plastic toggle switch covers. The round aluminum toggle caps of the 150 and 606 lineup look much nicer to my eye.