Not percivaliana. If it has a very large plant and the flowers are 4"-5" across, I'd say Lc. Vandaletta, but it might be hard to ever be sure. The flower looks exactly like the Vandaletta I used as a parent with several SLC's back a few years ago.
I had it in the us. I'm living in Panama' now, but I may be able to find some pictures. I will post a picture tomorrow if I can find one. I'm classifying orchids here in Panama' and have a lot of pics to sort through.
Vandaletta is usually bifoliate with large leaves.