Voxengo msed is a good plug for decoding. :)
This has turned out to be a better tip than I thought. I'd forgotten there was an Inline mode, which is making a beautiful job of reversing my earlier c-u.
For those of you who don't know the plugin - it's free and available in 64- and 32-bit versions - there are three modes.
Encode: l/r -> m/s
Decode: m/s -> l/r
Inline: l/r -> m/s -> l/r *
* Essentially it allows you to rebalance the stereo width on the fly. Hello again, clarity!
Bit of an essential piece of equipment that I now understand the use of so much better than I did. Thanks, Woodcrest, you are the man!
A very :D C