Yes, an ALAN 2 to Inform source converter (minus the ugly score/turns on the status line, which Thomas settled with a cleaner SCORE:0 MOVES:0 classical output) is a capital idea… Who is still on it? 
It’s not hard to manually convert ALAN 2 code to Inform 7; you just need to have knowledge of the ALAN 2 syntax. …and anyone who has knowledge of both languages (as well as some sort of programming language) could probably make a converter.