Ok, using the idea of allnameswereout, I've compiled an PREEMPT kernel with the wireless working. But I have no way to prove it's preempt because I removed the preempt string

Of course, I have no way of telling if it's preempt so feel free to treat this like BS

What I just said about the /proc thing wasn't true . I just compiled another PREEMPT kernel with PREEMPT in the uname like normal and those proc entries were still not there. This still could be very likely a PREEMPT kernel.