Yes, I pretty much just traced them. The first pair came out a little small so I added some to the SA. Honestly, they're still smaller in size than the original pair that I traced (which I think is the size Small). I also cut down the rise quite a bit, because IMO the rise on the Hanna Unders are quite large.

I've never used the Otto under pattern, so I can't be sure. If you wanted to construct them just like this, I'm not sure if another pattern would work, but you could always try it. The reason I like this pattern so much is because the leg holes don't require elastic. I'm not sure how big the leg holes are on the Otto pattern and if they would sag if you didn't use elastic. KWIM?

That PRR is Reds Allover Stripe.