PDF: Multiple pages with different size on one page

I have a PDF with 6 pages (let's call dem A-F) in portrait format. (example file)

The pages have two different sizes:

• A,C,D,F: 101.5mm x 215.5mm
• B,E:9.9mm x 215.5mm (so they are a bit narrower)

Now I want to merge them to two pages (302mm x 215.5mm).

Page 1:
_____________________________
|         |       |         |
|         |       |         |
|    A    |   B   |    C    |
|         |       |         |
|         |       |         |
|_________|_______|_________|
Page 2:
_____________________________
|         |       |         |
|         |       |         |
|    D    |   E   |    F    |
|         |       |         |
|         |       |         |
|_________|_______|_________|

When I try pdfnup I get white borders between the files. (example)

pdfjam --suffix "print" --nup '3x1' --papersize "{302mm,215.5mm}" Dokument-2.pdf

Is there a better way to print multiple pages (with different sizes) on one sheet without resizing the pages?