Answer – From what you say I certainly think it sounds like you have a natural proclivity toward the craft. I do however think it is important to highlight the elements that support this reasoning. The feeling of your own power is deeply suggestive as is your feeling that you are somewhat out of time with the century you were born into. Above all the fact that you are drawn to being a witch and you keenly feel its absence in your life is a clear indicator that you are ready to take the step forward to studying the craft.
I am afraid though that neither your appearance nor your witch mark are all that relevant. In my experience there is no correlation between the expected image of the witch and the actual appearance of those who study the craft to success. Short fat bespectacled mousy haired witches are often those who wield the most power…
In terms of books on Traditional Witchcraft, you will find that there are actually very few about. A lot of books as you have discovered yourself have a very definite Wiccan bias and although some (Raven Grimassi, Doreen Valiente, Paul Husan) do have valuable information on older practices you will often find that you have to wade through a lot of muddy water to seek knowledge of the older ways. Forums are a different thing entirely and the opportunity to interact with those on a similar path can be invaluable. I am sending you a link separately to one of the best forums I have come across. There is an application process but I believe the site moderators look favourably on newcomers if they are honest about being a beginner who genuinely wants to learn.
A good understanding of history can be a great starting point for understanding the lives of our ancestors. Try to read around how normal people lived in older times, their dependency on the earth and how they incorporated the change of the seasons and the patterns of the moon into their daily lives. The witches of old worked closely with the natural world and I would advise you to broaden your own knowledge of the world around you. Study books on botany, herbs, even astronomy to create your own awareness of the world - start to think how you might begin to incorporate your environment into a magical path.
With Traditional Witchcraft there is no substitution for getting stuck in. Unless you are following a specific tradition or hereditary path that requires mandatory steps (and I’d avoid such things to be honest, they are usually Wiccan in origin despite claiming to work with knowledge preceding the mid 19th century Wiccan religion) then you have the freedom to start expressing yourself at the most intuitive level.
Write some basic spells. Start with a framework from a book if it makes you feel more confident (Element Encyclopedia) but then start to alter and adapt the spells to fit better with your own intuition and what you are learning from your reading of the natural world.
There are of course restraints on what will/won’t work with magic – herbs for example have specific properties and these need to be learned and understood. But in terms of the craft itself, the ability to connect with your own power comes from within and no book can teach it. So my advice is to read as much as you can around the peripheral ”science” of magic (herbs/crystals/divination – whatever appeals) and not simply to seek out books that claim to teach the craft, because they won’t. Work a blend of the knowledge you acquire into a determination to have a go and that will give you a better foundation for witchcraft than any book ever could.
Image http://www.sxc.hu/browse.phtml?f=view&id=1430242 (MrsPeel)