There are ways to get around to resolve your requirements without doing much more lisp coding.
But you've left out the most important information of all such as:
1. Provide the steps you take to manually create a PDF of one of these sheets that would meet your requirements ie: Sheet Size A1 or A2, name of ctb file that would make the lines match your requirements, plot scale, 1:15 or Fit, origin 0,0 or to center? All this information would need to be included in the lisp code like the way I've done it for you before.
2. What program if any do you have to modify individual pdf files such as Adobe Acrobat or Bluebeam? Acrobat for example provides the option to combine individual PDFs and re-order the pages into a single multi-page PDF file.
3. Would it be a problem for the original drawing sheets after you've copied them below to have Title blocks that are exploded so they won't be included when the Demo lisp code runs? You can also Undo the Explode after the PDFs are created.
4. Since the first sheet has a different title block name instead of the same title block name as the others, this is why Demo lisp code did not pick this up. Remember the Demo lisp code was originally written to accommodate for a single title block name A1- which I modified to accommodate only for a single title block name in your drawing. You can always make a copy of Demo and call it Demo1 and modify the code there to pick up the first sheet title block name.
