I once tried tracking down a HD dendro. I managed to find out it was grown by a company called American Mercantile. I think out of Homestead Fl or close to it. The place is HUGE. Even though there was a number on the tag. They were only able to approximate the breeding line, and not well enough to get any parentage.
I've seen lots of these mini-Dendrobiums, some are pink/magenta lip like this, some are white with magenta lip. I think they are either Den. bigibbum or hybrids thereof: http://orchidspecies.com/denbiggibum.htm/ They are very floriferous, like this one, flowers are long-lasting, and may even bloom more than once a year.