Interesting questions... I'm more interested in what the name conveys to the consumer - if they feel misled, that's a fail. So if your wild brew has some reasonable resemblance to a Lambic, pLambic and Lambic-style are fine (and "Oud Bruin met perzik" for your brew is a great name, since you've followed the Oud Bruin style. Country of origin seems like good back label text if you're so inclined).
Early brewers did not understand all the mycology going on with yeast, but they surely recognized that there was something going on besides water, malt, and hops, and that using the dregs from a clean-tasting beer somehow increased the chances of getting another.
I'm interested by the idea that people do "wild ferments" - that's putting a lot of faith in local microbes, given the work/expense put into the brew. I've never tried to do this intentionally, but in 18 years of brewing I've certainly made infected batches, and have had numerous infected brews imposed upon me by homebrewing pals looking for a diagnosis. It seems that the "unusual" flavors from the uninvited critters are mostly in 3 categories: phenolic, sour, and earthy. And these general elements are all in Lambics. Unfortunately, phenolics can be pleasant (e.g., many Belgian styles, German weizen), or absolutely vile. My experience with infected brew has always been the latter. Sour can also be interesting (e.g., your Oud Bruin, Berliner Weisse, ...). My only "sour" infection was pretty clean and lactic. I didn't like it, but my 2 brew partners fought over it. I like "earthy" in small doses - but I never detected that je-ne-sais-quois essence of a nice biere de garde in any of these infected batches.
Other experiences?