Steve, welcome to the Group. If this tree was professionally wired or not, is not an issue in what you are desiring to do. First, this tree looks to me like it wants to be an informal upright. Working with the tree and where it wants to go is much easier than trying to force it into a Formal upright.
In addition, to my limited knowledge the two most difficult styles (to do correctly) are windswept and formal upright. I STRONGLY suggest you go the informal upright style with this tree.
In addition, looking at the wiring in the picture, I question it being professionally wired. Sorry, but that is my opinion. I do think if you can find a Bonsai Club near you, they will be able to advise you as to how to go. They may be able to point you in the direction of someone (possibly a club member) who could help/advise/teach you.
my two cents