How to merge different abap-list spools, xstrings or binary files to one PDF

Hi out there,

i'm not able to solve my approach. And i#m not able to find any clearly answers by searching different boards.

So...

I'm reading some abap-list spools (NO OTF!!) and i want to merge the content into one PDF document. With OTF it's no prob.

But it#s difficult to solve with abap-spool-list.

So after unsucsessfully approaches via RSPO_RETURN_SPOOLJOB or CONVERT_ABAPSPOOLJOB_2_PDF' I'm now on this:

select * from tsp01 into i_tsp01where rqident in spool.
   append i_tsp01.
endselect.

 data :
           l_file type  xstring,
           l_size type  i,
           lt_file_tab type table of x255,
           lt_file_tab_final type table of x255.

loop at i_tsp01.
   clear: tab1, eof.
   refresh pdf.
clear: l_file, l_size.
call function 'FCC2_SPOOL_TO_PDF'
   exporting
     i_spoolid               = i_tsp01-rqident
  importing
    e_file                  = l_file
    e_size                  = l_size
  exceptions
    spool_not_exist         = 1
    cannot_create_pdf       = 2
    others                  = 3.

call function 'SCMS_XSTRING_TO_BINARY'
   exporting
     buffer                = l_file
    append_to_table       = ''
* IMPORTING
*   OUTPUT_LENGTH         =
   tables
     binary_tab            =  lt_file_tab   .

append lines of lt_file_tab  to lt_file_tab_final.

 endloop.

 call method cl_gui_frontend_services=>gui_download
exporting
   filename                = file
   filetype                = 'BIN'
changing
   data_tab                = lt_file_tab_final
exceptions
   file_write_error        = 1
   no_batch                = 2
   gui_refuse_filetransfer = 3
   invalid_type            = 4
   no_authority            = 5
   unknown_error           = 6
   header_not_allowed      = 7
   separator_not_allowed   = 8
   filesize_not_allowed    = 9
   header_too_long         = 10
   dp_error_create         = 11
   dp_error_send           = 12
   dp_error_write          = 13
   unknown_dp_error        = 14
   access_denied           = 15
   dp_out_of_memory        = 16
   disk_full               = 17
   dp_timeout              = 18
   file_not_found          = 19
   dataprovider_exception  = 20
   control_flush_error     = 21
   not_supported_by_gui    = 22
   error_no_gui            = 23
   others                  = 24.
if sy-subrc ne 0.
   write sy-subrc.
endif.

With one spool id: OK!

With two spool ids: Only the last spool-content is shown in pdf. Even the pdf is doubled sized the before. Just the last content.

Any Idea? Thank you!