These are sources to one of the earliest Modula-2 compilers from ETH that generated code for a PDP-11 from around 1981. I don't know whether this has been published anywhere else or where it fits in Modula-2 history. The best historical information I have is from Gunter Mueller's Github site.
Note that it generates PDP-11 binary code directly, not PDP-11 assembly.
I have uploaded this to Github for historical interest for anybody who wishes to study the software.