Looks like an 86 to me.....just like mine!
Too bad about the drew job done on the shifter bosses. Not sure how ALAN anchored the shifters on the DT, but if it had a thin bolt going across from one boss to the other through the DT, a few C&V bikes from the 80's used such, and you might be able to adapt it over to your frame, if you cannoy find a set made by ALAN.
Otherwise, a clamp on from Simplex or Campy would look good too.