I haven't seen these plants for ages, Giles - I hope someone can up with a source . Not only P. sinensis, but also Primula malcoides and P. obconica used to be popular - my Grandfather and Uncle always grew lots of them ( and yes, the plants did bring me out in an itchy rash!) and they make super house plants.
I think I did see a few scruffy obconicas a year or so ago, but they were in such a bad state I wasn't tempted.