Attached the shell scripts using awk and sed how I have migrated two separated logbooks into one single and how I re-adjusted certain attributes.

#!/bin/bash
# KR84, 28.10.2019

# generate emtpy auto-fwd text for LLRF for 3100 entries and offset of 2000
echo "generated import_llrf_fwd.xml"
echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" > import_llrf_fwd.xml
echo "<ELOG_LIST>" >> import_llrf_fwd.xml

declare -i ID
declare -i IDNEW

for ID in {1..3013}
do
    IDNEW=$ID+2016

    echo -e "\t<ENTRY>" >> import_llrf_fwd.xml
    echo -e "\t\t<MID>${ID}</MID>" >> import_llrf_fwd.xml
    echo -e "\t\t<DATE>Mon, 28 Oct 2019 20:00:00 +0200</DATE>" >> import_llrf_fwd.xml
#    echo -e "\t\t<DATE>28.10.2019 20:00:00</DATE>" >> import_llrf_fwd.xml
    echo -e "\t\t<ATTACHMENT></ATTACHMENT>" >> import_llrf_fwd.xml
    echo -e "\t\t<ENCODING>HTML</ENCODING>" >> import_llrf_fwd.xml
    echo -e "\t\t<When>28.10.2019 20:00:00</When>" >> import_llrf_fwd.xml
#    echo -e "\t\t<When>1572289200</When>" >> import_llrf_fwd.xml
    echo -e "\t\t<Author>Kalt Roger (KR84)</Author>" >> import_llrf_fwd.xml
    echo -e "\t\t<Machine>SwissFEL</Machine>" >> import_llrf_fwd.xml
    echo -e "\t\t<Domain></Domain>" >> import_llrf_fwd.xml
    echo -e "\t\t<Section></Section>" >> import_llrf_fwd.xml
    echo -e "\t\t<System></System>" >> import_llrf_fwd.xml
    echo -e "\t\t<Subsystem></Subsystem>" >> import_llrf_fwd.xml
    echo -e "\t\t<Subject>Automatic forward</Subject>" >> import_llrf_fwd.xml
    echo -e "\t\t<TEXT>&lt;meta http-equiv=&quot;refresh&quot; content=&quot;0; URL=&apos;https://elog-gfa.psi.ch/SwissFEL+RF/${IDNEW}&apos;&quot; /&gt;</TEXT>" >> import_llrf_fwd.xml
    echo -e "\t</ENTRY>" >> import_llrf_fwd.xml
done

echo "</ELOG_LIST>" >> import_llrf_fwd.xml