Just to comfort you a little -- while you missed out on a good deal, probably not worth too much agonizing. The 7t was the replacement for the 7c, which was tubes and probably one of the great preamps of all time. The 7t shared its ravishing good looks, but not the sound. It has the clarity and lack of distortion of solid state, but also the transistor sound. Good, but not great. Build quality is top notch, but its an old component by now, so might need repairs and parts might not be neccessarily easy to find.
And other stuff is just waiting out there for you...