My property is pretty well forested, and shrub landscaped closer to the house. The house itself was built in the 50s, and most not-natives are from the original owners, who sold their home in the early 80s to the people we purchased it from about 15 years ago. Unfortunately, we don't have any larger JMs throwing seeds for us. So, many of the stumps, all of teh JMs, anyway, come from my in-laws' property. Most of them are at least a few years old. Since they've sold their home, I took as many of the larger, easier to get ones as I could, about 18 of them. Everything other than the JMs comes from my property.
It's funny, I see people have relandscaped all of the time, but I can never seeem to catch them "in the act". I've placed ads in the past, asking for seedlings and saplings. That's pretty ridiculous as well because once people find out someone wants their crap, it all of a sudden becomes worth its weight in gold. For instance, one person wanted $2 each for first year JM seedlings. She came down to $1 after I told her they were worthless. Another person (from last year) just contacted me again about a shrub (that I've already told them I'm not interested in) that is fairly large. I told them I'd dig it out for free, but they wanted $50 on top of that. So, it's not like yamadori are not available, they are, but once someone hears that it's "for bonsai", they get kaCHING dollar signs in their eyes, not realizing that it's not the stump that has value, but the artist's work.
I'll see if I can get some other angle photos today or next weekend. Today's pretty full on the bonsai front, as I have several airlayers and collections also waiting for me.