Radiotechnique 12AU7/ECC82/6189 Sonics

Thanks for the input, but a broad coharacterization and general history isn't what I'm looking for. I'm interested in the specific sonic differences between the long and short plates, between the various years of each, and between the 12AU7 and the 6189 versions.
Apparently there were some long plate versions of the made in 1958.

I don't expect to find a single person with comprehensive knowledge of this tube, but surely there are a few with enough exploration of it to be able to piece together a sonic profile. Moreover, I don't believe the audio world is so utterly atomistic that nobody can sat what any tube sounds like because of the uniqueness of every circumstance. What I'm interested in, specifically, is the difference (if any) between the long and the short plates, and between the regular 12AU7 and the 6189.