Sunflowerzz, I would love to see a photo of the bobbin, bobbin case, and how to get to it!
Wondering, because I have never seen a Pfeffer 130 or 131 in person, but my Anker Phoenix is purported to be a Pfeffer 130 knock off, and its bobbin case is a bit unusual (has a wee hook on the exterior for the thread to pass through) and is also funkily hard to get to. I would be so curious to see yours, if you are inclined to post some close-ups!