Ross, you are rapidly becoming my hero
The pdf is a "non-standard" size as it is an instruction leaflet and yes the writing has slipped down a bit in your DR Merge.
As you request, here is a quadranted page with crosses, numbers and some text on it. It is the Quad template from grumpyoldman. Now, as it is a writepad, I can actually merge this in the PC software but pdfs elsewhere, are not seen in the companion software I have.
I enclose the original metadata & Quad template.
The result of the PC merge & the result of your DR Merge.
thank you, Howard