I have seen 81s with the regular 5 bolt hubs and some with the 6 bolt offset or wavey hubs. I'm fairly certain either one was correct at some point during the production of the 81s. I tried switching my 101 Junior over from a 6 bolt offset hub to a regular 5 bolt because I couldn't find any good replacement wheels for it. I unfortunately found the 5 bolt hubs won't work on the 6 bolt spindles so I had to try harder to find the correct wheels. So I would say it's just fine the way it is. And besides, I like the look and uniqueness of the wavey hub and wheel.
Bob