The description of M. eumorpha calls for a plant from Villa de Reyes, San Luis Potosi, which is a long way over the mountains from Tamaulipas - see Wolter ten Hoeve's posting on the M. roseoalba thread. So I doubt if M. eumorpha has anything to do with M. roseoalba at all. In the description of M. eumorpha in the AfM Journal (3: 2008) the suggestion is made that it belongs close to M. gigantea or M.saint-pieana.
I have a couple of M. eumorpha plants, fairly young which I've had for just a year, of Rep 2264, but they haven't flowered yet. They seem to be busy building up the woolly axils at the moment.
They are similar to Ento's plant certainly, though the description says that the stigma and style are yellow, whereas the photo makes them look pink. This appears to be OK, though as the photo below is taken from the AfM article of 2008 where they also look pink. So I think we're talking about the same plant!!