Just for reference, I'm a newbie looking at "fat" tree trunks and wondering posibles.
I understand perfectly why
@Alain says "I would never try to collect such a tree", and based on that realization I truly question my sanity looking at certain trunks. If you don't understand why, I suggest you get in your head the "required
annual process/progression" and years (decades?) required of turning a deciduous into a bonsai, because it is absolutely opposite the evergreens, which in many cases can be yamadori'd and trimmed into a nearly finished, (or at least be able to have something show worthy to family and friends, who are less critical of certain bnutters and true bonsaists).
Last year I brought home 1/8th inch minus "trees" because of the tight internodes. That was a mistake because of the length of time required to achieve anything resembling a "bonsai". This year I've tended to wander to the opposite extreme of the pendulum and am looking at "fat" trunks, many like yours without any branch approx. half the dia. of the trunk and especially none on the trunk that will be part of the bonsai, ("a mistake because of... time???").
All that said, I'm looking at your first picture and drawing an imaginary dotted line for an air layer spot below the wound/hollow/scar that is below the crook of the slingshot. But the more I look at it I wonder what the heck was I thinking.
On the pendulum of too small/too long/too many details to overcome and the other extreme of too big/too long/too many details to overcome there is a sane/reasonable/appropriate spot that certain pre/prospective bonsai fall into. These are the trees that tend to be searched out and brought home to be worked/developed/even appreciated over the following years.
If you have a good understanding of that mid category, please p.m. me those specific details because I'm still simply learning by the seat of my pants and the mistakes I make, swinging from one side of the pendulum to the other. If you already understood what I tried to get across in this post, please forgive me, and disregard all I said.