thats good to know. so you would consider this younger stock?
LOL, yes I would. Yamadori of that age I do consider younger. I guess it is what one is exposed to.and used to collecting! It makes sense that it was collected at high elevation to have that bit of mature bark on that size of a trunk. The majority of the tree has immature bark, showing sap cells just below the surface and smooth surface, the base of the tree is beginning to show some age with scales forming on the bark. This is a positive because the upper portion will be the target for future branch and foliage development. The spindly branches low down will be more difficult to strengthen and develop.
If I had just acquired the tree, I would repot, placing the tree deeper in substrate and bringing it back to health for two years before any other work. A bit deeper grow box built just to enclose the current root ball with 1 inch to spare. Regardless of how long ago it was collected, it appears weak and in need of strengthening, repotting will tell you exactly what the condition of the roots are and what amount ( if any) of native soil is left to deal with. Also, it will perhaps explain why it is planted so high and exposing so many smaller roots on the one side.
Once it is in better condition, it appears that removing those finer roots on the left side will reveal a very nice flare to complement the lower flare on the right side.
In short I think you have a tree with fine potential, the first priority would be to get it back to health and I do not believe one can do that without understanding exactly what the overall condition of the roots are.
I will admit to a firm bias, I do not like to develop trees or bring them back to health in Bonsai pots. I prefer to transfer them to Bonsai pots after they have developed the fine root system that allows them to thrive in pots and the major development work has been completed.