I would say it can be done.
I have a FIvemega body that`s for P series Surefire lights and my Malkoff HDS screws onto it but it doesn`t sit all the way down.
It needs to be cut and threaded close to the neck in order for the head to seat all the way.
I haven`t done it yet but I would suggest contacting Barry from Precisionworks.
He`s bored a few Surefire lights for me to take 18mm cells. I would bet he could do what you ask.
The one thing you might lose is the high/low function if there`s not enough to keep the thick lip on the body where it screws into the head of the light but again, you would have to ask if that`s possible to retain that function.