Okay...just wanted to get clarifcation on which transformers you had in mind. Yes, a Line-to-mic level transformer will offer 20dB of attenuation on average, which should be equivalent to the "pad" circuit I drew above. And many of the line-level transformer primaries measure 20k ohms, there should be only a fractional amount of power flowing through the input side. I handn't considered using a matching transformer, but it seems it would work well.
I'm familiar with the Jensen transformer company. Thanks for the link.
Do you, by chance, know this company, who also make high-quality transformers--(all manner of them, in fact)?