I've tried using the OED as a guide, but they use that darn IPA notation.

Funny. The IPA is no less or more arbitrary than the ad hoc systems. If you can take the time to learn one of those, you can learn the IPA. The real problem I have with the those other systems is that they're based on pronunciations in words, and as we all know many words differ in pronunciation from region to region. But you are free to use your system. It's just that I won't be very much helped by it.

Ceci n'est pas un seing.