Hi Jim
The standard Meteor MK6 is about the nearest I can find to that spec after cutting but again the OD is only 18.8mm.
Have you tried sleeving the Hawk transfer port down to 2.5mm yet (you'll need to use a Vulcan breach seal) ?
I sleeved My HW35 down from 4mm to 2.3mm yesterday, the power hardly altered but the firing cycle was transformed and the chrono keeps reading dup.
I still can't believe all that air could get through a 2.3mm hole.
You really must try it on your Arnie
All the best Mick