Hey all- well, she's back from the shop. Radiator was replaced, and the support was repaired. The support was pushed in on one side, and pushed back- so since I (lightly) bumped the curb straight on- the theory remains that there was probably previous damage from the PO hitting something that I worsened.

The tranny checked out OK after all- and after a thorough test drive, it was theorized that when I hit the accelerator pedal to leave the parking lot, the slight rise in rpms and the rubbing of the fan on the shroud freaked me out and I thought tranny, flare, metal noises, etc EEK!. It's driving as before now- and there's no clunk. The only thing I can think of that might have caused the clunk was that I had some crap in the trunk that might have rolled around back there- because I took everything out- and now it appears to be clunkless. (Yes, I am willing to admit that trunkstuff might have created a possible symptom...) So, I wanted to post to close out the thread, because that's what you're 'sposed to do. Thanks to all who posted!