I've spent (quite) a few hours this weekend updating my 2.11BSD GitHub Action (yes, you ca do continuous integration testing against a PDP-11 ) to support all patch levels from 450 to 479.
The best thing about this is that it demonstrates that the patches still work and can be applied as described, but also that you can test your PDP-11 software without needing to boot up your PDP-11...
To complement this, I've finally managed to apply all patches to the source tree in Git. Each patch was built separately using a copy of _this_ source tree, rather than the one inside the image. They all pass, after fixing a couple of small issues.
The next thing I want to work on is building new distribution tapes for each patch level.
@asj @troglobit Check out this github action for running stuff in a fully patched version of 2.11BSD on a PDP-11.