I was able to compile pnm2ppa, of course no way for me to test this without the right hardware.
I uploaded the folder containing the compiled binary to my dropbox
You can download the zip file, extract it and enter the folder pnm2ppa-1.13
Now, you need to install first make and foomatic with
sudo eopkg it make foomatic-db foomatic-db-engine
then in the pnm2ppa-1.13 folder run sudo make install
This should install pnm2ppa
To test this, run pnm2ppa
in terminal
Check also /etc/pnm2ppa.conf
again. You might have to set version to 710.
Then try again to set up the printer in browser via http://localhost:631
with the right ppd file as described earlier.