diff --git a/roles/kolibri/tasks/main.yml b/roles/kolibri/tasks/main.yml
index e3fdc8e9b..5c2ccd757 100644
--- a/roles/kolibri/tasks/main.yml
+++ b/roles/kolibri/tasks/main.yml
@@ -25,23 +25,27 @@
     group: root
     mode: 0755
 
+# 2019-10-14: An alternative might be to put KOLIBRI_USER="kolibri" into
+# /etc/kolibri/conf.d/iiab.conf
 - name: Save kolibri_user ({{ kolibri_user }}) to /etc/kolibri/username
   copy:
-    content: "{{ kolibri_user }}"
+    content: "{{ kolibri_user }}"    # i.e. kolibri
     dest: /etc/kolibri/username
     owner: root
     group: root
     mode: 0644
-    
+
+# 2019-10-14: An alternative mentioned by @benjaoming (Benjamin Bach) would be
+# to put KOLIBRI_HOME="/library/kolibri" into /etc/kolibri/conf.d/iiab.conf
 - name: Save kolibri_home (KOLIBRI_HOME="{{ kolibri_home }}") to /etc/kolibri/daemon.conf
   copy:
-    content: 'KOLIBRI_HOME="{{ kolibri_home }}"'
+    content: 'KOLIBRI_HOME="{{ kolibri_home }}"'    # i.e. /library/kolibri
     dest: /etc/kolibri/daemon.conf
     owner: root
     group: root
     mode: 0644
 
-- name: apt install latest Kolibri .deb from {{ kolibri_deb_url }} (populates {{ kolibri_home }}, migrates database)    # i.e. /library/kolibri
+- name: apt install latest Kolibri .deb from {{ kolibri_deb_url }} (populates {{ kolibri_home }} / migrates database, based on params set in /etc/kolibri)
   apt:
     deb: "{{ kolibri_deb_url }}"    # https://learningequality.org/r/kolibri-deb-latest
   environment:
@@ -96,13 +100,15 @@
   become_user: "{{ kolibri_user }}"
   when: kolibri_provision | bool
 
-- name: chown -R {{ kolibri_user }}:{{ apache_user }} {{ kolibri_home }} for good measure?
-  file:
-    path: "{{ kolibri_home }}"     # /library/kolibri
-    owner: "{{ kolibri_user }}"    # kolibri
-    group: "{{ apache_user }}"     # www-data (on Debian/Ubuntu/Raspbian)
-    recurse: yes
-  when: kolibri_provision | bool
+# 2019-10-14: This stanza should not be necessary according to @benjaoming
+# (Benjamin Bach) especially as migration & provisiondevice were run above.
+#- name: chown -R {{ kolibri_user }}:{{ apache_user }} {{ kolibri_home }} for good measure?
+#  file:
+#    path: "{{ kolibri_home }}"     # /library/kolibri
+#    owner: "{{ kolibri_user }}"    # kolibri
+#    group: "{{ apache_user }}"     # www-data (on Debian/Ubuntu/Raspbian)
+#    recurse: yes
+#  when: kolibri_provision | bool
 
 
 # 2019-10-07: Moved to roles/httpd/tasks/main.yml
diff --git a/roles/lokole/tasks/install.yml b/roles/lokole/tasks/install.yml
index c1033b8fe..194472ac6 100644
--- a/roles/lokole/tasks/install.yml
+++ b/roles/lokole/tasks/install.yml
@@ -1,7 +1,7 @@
 # Lokole PDF (User's Guide) gets copied for offline use (http://box/info) here:
 # https://github.com/iiab/iiab/blob/master/roles/httpd/templates/refresh-wiki-docs.sh#L47
 
-- name: "Install 7 packages for Lokole: python3, python3-pip, python3-venv, python3-dev, libffi-dev, libssl-dev, bcrypt"
+- name: "Install 7 packages for Lokole: python3, python3-pip, python3-venv, python3-dev, libffi-dev, libssl-dev, python3-bcrypt"
   apt:
     name:
       - python3
@@ -10,7 +10,8 @@
       - python3-dev
       - libffi-dev
       - libssl-dev
-      - bcrypt
+      #- bcrypt does not exist on Ubuntu 19.10
+      - python3-bcrypt    # 2019-10-14: should work across modern Linux OS's
     state: present
   tags:
     - install
diff --git a/roles/osm-vector-maps/tasks/main.yml b/roles/osm-vector-maps/tasks/main.yml
index c4f8ac726..dd25b7afa 100644
--- a/roles/osm-vector-maps/tasks/main.yml
+++ b/roles/osm-vector-maps/tasks/main.yml
@@ -34,9 +34,10 @@
     url: "{{ iiab_map_url }}/assets/bboxes.geojson"
     dest: '{{ vector_map_path }}/maplist/assets/'
 
-- name: Install python-geojson package, that helps with geojson
+- name: Install python3-geojson package, that helps with geojson
   package:
-    name: python-geojson
+    #name: python-geojson does not exist on Ubuntu 19.10
+    name: python3-geojson    # 2019-10-14: should work across modern Linux OS's
     state: present
 
 - name: Install /usr/bin/iiab-update-map for updating of Map Pack catalog & descriptions
diff --git a/vars/debian-10.yml b/vars/debian-10.yml
index f823408e9..9c82440f6 100644
--- a/vars/debian-10.yml
+++ b/vars/debian-10.yml
@@ -25,5 +25,5 @@ php_version: 7.3
 postgresql_version: 11
 systemd_location: /lib/systemd/system
 # Upgrade OS's own Calibre to very latest:
-calibre_via_debs: True
-calibre_via_python: False
+calibre_via_debs: False
+calibre_via_python: True
diff --git a/vars/ubuntu-19.yml b/vars/ubuntu-19.yml
index 5b89d04fc..d6afbcf33 100644
--- a/vars/ubuntu-19.yml
+++ b/vars/ubuntu-19.yml
@@ -22,7 +22,7 @@ mysql_service: mariadb
 apache_log: /var/log/apache2/access.log
 sshd_package: openssh-server
 sshd_service: ssh
-php_version: 7.2
+php_version: 7.3
 # "postgresql_version: 11.2" fails (too detailed for /etc/systemd/system/postgresql-iiab.service on Ubuntu 19.04)
 postgresql_version: 11
 systemd_location: /lib/systemd/system