N_Cook Inscribed thus:

But it only takes one person to crack it and divulge to wwwland and
their competitive advantage is lost - strange old world

Too true !

Is there in enough facetting left in the TORX holes to grind down an
Allen key to near enough match to get enough purchase. Preceeded by
heating with a soldering iron a timed number of seconds, gradually
getting more adventurous with the seconds on repeated attempts, after
cooling off periods

Heating for a timed period is the way I would go. Ten to fifteen
seconds would be a good period. Though if thats what their own techs
do I wouldn't worry too much. On the other hand their own techs will
have access to spares should they damage anything.

Drilling out is likely to heat up anyway in a less controllable way.
If you do drill out use a left hand drill bit (if unavailable from an
engineering supplier then regrind a normal one with the other
set/rake) and left hand action drill

Oww ! Trying to regrind a drill that small is going to be a major pain
in the butt... !

--
Best Regards:
Baron.