Hi Michael, I've uploaded to https://mentors.debian.net/package/network-manager-l2tp , hope it looks okay. If so, I'll commit the changes to https://github.com/nm-l2tp/debian
One minor difference, I just changed the order of two override_dh_auto_configure lines in debian/rules to match network-manager-pptp. I'm in process of implementing a new network-manager-l2tp 1.8.0 that uses the NMACertChooser API introduced with NetworkManager 1.8.0, but is a number of weeks away if not more. Once I create a new deb package, will make sure to I sync with the network-manager-pptp deb package. Cheers, Doug