As the sghian dubh was supposed to be a 'black knife' some of the nicest ones I have seen are the simplest bog-oak handled; not fancy or highly decorated. I know a lot of the modern variations can run from dummy plastic ones to very fine pieces of work, so I guess it comes down to the purity of the intention. Whilst I would love a really simple, clean cut bog-oak handle I've had to settle for the cheaper, decorated version. It doesn't feel as authentic - but then as you've mentioned with the licensing laws, the chances of the handle staying intact for anything other than opening the post are extremely remote so it should be fairly safe
Phil