I tried finding out more about this variety and where it came from. Botanica's Roses is the only published work that lists it, as far as I know.
Treloar nursery says that it was bred by LeGrice in England, 1990. I've made inquiries with LeGrice and they've never heard of Ernest's Blue! Does anyone know more about this rose?
Sorry to answer my own question like this, but here is what Treloar Roses told me when I inquired further:
"Hi, It certainly is a LeGrice rose, we had it for many years before releasing it. Mr LeGrice used to send us many roses to try out, a lot of them were never released in England, this may have been one of them."
Apparently it is a very full bloom, so the answer should be yes. I am trying it out this year and will post photos when I can. See the link for photos from my supplier: http://www.treloar-roses.com.au/files/ernests_blue.htm