Burr is short for Burrageara, in the Oncidium alliance. It's a Cda x Milt x Odm x Onc. Those are: Cochlioda, Miloniopsis, Odontoglossum and Oncidium.
Nelly Isler, or more correctly, Memoria Nelly Isler, or Mem. Nelly Isler is a lovely red! How nice that yours is fragrant to boot!