Installing Lektor using the curl command from getlektor.com appears to work and appropriate files are present in the /usr/local/bin/ directory after the process completes.
However, which lektor shows nothing despite /usr/local/bin being in the path.
This turned out to be a python version problem. Invoking python on this machine starts a python 3.x environment and the lektor install script is expecting python 2.x.
The problem can be solved by downloading the install script to a file and changing the line that invokes the python script:
$ curl -sf https://www.getlektor.com/install.sh > install.sh
Edit line 19 of the install.sh file to invoke python 2.x (in this case I have python 2.x installed and linked as python2):
...
16 exit 1
17 fi
18
19 python2 - <<'EOF' <- change here from python to python2
20 if 1:
21
22 import os
...
then change the mode of the script to be executable and run:
$ chmod +x install.sh
$ ./install.sh