First of all thanks for the insights. I actually went ahead and collected the object_id manually without changing file.vuh.
Learning that the object_id is actually the package_id is disturbing, I thought it really was the displayed_object_id. And obviously then the code I wrote makes absolutely no sense at all. Thanks for clearing that up Dave. In this case I will deduct the object_id from the URL in general. Especially as this is only a side topic for me 😊.