Great! Glad it worked. Happy to help you unpick things a bit further. When you look inside the pdf file you’ll see that it’s actually a “tree” of “things”. Each one starts with “obj 0 1234” (or something like that). And they reference each other to build the structure. So for example, the document is made of a list of pages. So that’s one object. And each page is another object. And then each page is made of a bunch more stuff and so on. Somewhere in there, no doubt, you’ll find an object that’s your model.