Finally resolved the issue that I’d passed on a few days ago.  With some help from the chaps over at the interactive fiction forum I finally found a method to return the location of Huey, Dewey and Louie to the player when the player examines some monitors that are found around the Valley Forge.  The final code was:-

Object monitors “bank of monitors”
with name “monitors” “monitor”,
description “There are three monitors, each one showing a live feed from the freighter’s maintenance drones.”,
found_in droneroom crewsmess,
after
[; examine: Print “^Huey is in:-  “;Print (name)parent(drone1);Print “^Dewey is in:-  “;Print (name)parent(drone2);Print “^Louie is in:-  “;Print (name)parent(drone3);
],
has static controlled;

The next thing I’d like to resolve is having the drones follow you when instructed rather and having to ‘take’ them which is the current situation.  Apart from that I realise I probably don’t have enough time left to sort out the various bugs and weird behaviour resulting from unexpected player input.

I’ve been reading creator of Inform Graham Nelson’s Craft of Adventure which is an interesting essay with five articles on the craft of creating interactive fiction.  In it he writes:-

It’s Never Finished

Games are never finished.  There’s always one more bug, or one more message which could be improved, or one more little cute reply to put it.  Debugging is a creative process that adds to the life of the game.

In the case of his own game Curses he writes:-

The play-testing process has increased the code size of ‘Curses’ by about 50%: in other words, over a third of a game is devoted to ‘irrelvant’ features, blind alleys, flippant replies and the like.

I’ve learnt just how much I’d underestimated the time required for this stage of the development and it’s given me a new appreciation for how tightly coded the original Infocom games must have been.