Cute little tree! It does appear to be growing for you.
On a collected tree like that, there are no "unwanted branches" to remove. Use everything. Maybe 5 years from now once you have a lot more back budding and density, you could consider removing some branches, but not yet.
If you value this little guy, I would basically leave it be for at least another year to gain strength before styling.
Thanks for your input Adair, but I think I'll respectfully agree to disagree on a couple of points... I don't generally rely on a certain amount of years to dictate how I work on a tree, instead, how it is growing and responding are my guides. This tree is growing, IMHO, plenty strong enough to allow for the setting of main branches. -- Also, from my experience (granted I don't have as much as many here) wiring main branches into shape has not hindered back budding.
This tree is valuable to a degree to me, though I have several far more valuable Limber pines, and this one is a good "guinea pig", so to speak. I have trees that were collected years before this one that I haven't worked on yet because I don't feel they are growing strongly enough to allow for the work, so I may be impatient... but I don't feel that is the case here.
As for "unwanted branches"... There is one branch in particular that is too thick - too high and too sparse to be of any use to me. If I want a branch there I would be better off grafting one smaller and with foliage closer to the trunk. -- I may use this branch as a jin; But as a branch it is "unwanted" in any future design I see for this tree. This is not out of disrespect for an older collected tree but simply a decision reached by looking at the tree from my own artistic point of view. I'm fully aware that others may see a different design than I do, but that's part of art... individuality.
I do appreciate your input and would be happy to hear any reasons you may disagree with my above stance.
Were all learning here.