OK, Marco, here are some of my plants:
M. evermanniana grown from MG seed 640.9
M. evermanniana grown from DeH seed 528
M. evermanniana Lau 1272, and interesting a rather woolly form
And now for a couple of baxterianas:
First a plant named as pacifica, itself a form of baxteriana
and just a baxteriana
So there's a sample, of the plants - they are different, mostly evermanniana is whiter as I said before....but how different?
I hope this helps...