Barrel of laughs. Sheered adjuster on Specialized Allez

One of the most fiddly and annoying things ever to happen to my Specialized Allez  was when I discovered that one of the downtube barrel adjusters had sheered off leaving the thread encased inside the downtube boss.
I discovered this as I was in the process of stripping it down to upgrade the group set to Shimano 105 - off the peg you get a mix of Sora and Tiagra.
After loosening the cables off and pulling them back through the shifters, I found the thumb twist top of the rear mech adjuster on the floor and the thread still in situ.
Ah ha, I thought, long-nosed pliers will do the job.  If I can get a good enough grip from the underside, a clockwise turn should see it out.  No chance.
Despite the lower part of the thread protruding enough to get a grip on it, there was no way I could get the required purchase.
Plan B.  If I drive a screw into it from below, that might help turn it out the other end.  I found the perfect screw for the job and began turning.  A couple of turns in, a satisfying 'click' sound came from the frame.  Removing the screw I found about 3mm of the adjuster thread had been stripped away by the screw.  Smugly satisfied, I shone my torch into the boss to view my handy work. Bugger!
All I'd successfully managed to do was remove the lower section of the adjuster thread up to the point where it engaged with the thread inside the boss.  So I now had around 3mm of adjuster thread stuck fast inside the boss.
There was only one thing for it - fetch the drill.
I was really apprehensive about taking a drill to my bike but it was the final option really.  I figured that as the adjuster thread is hollow - to allow the cable to run through - if I could drill in a reasonably straight line, with the right sized bit, I should be able to remove the last piece of adjuster thread without stripping the boss thread.
3mm bit looked about right and if you ever have to do this, use a drill with a variable speed - one that starts turning very slowly.  On the first attempt, I felt the bit engage then as I increased the load, disaster, a high-pitched 'ching' sound and the bit had snapped.  On to my second and only other 3mm bit, same procedure and I watched as a thin cork-screw of black metal turned out of the bit.
Looking inside, it looked pretty good.
Using the opposite side adjuster which had been removed in tact, it screwed in and out just fine - it bloody worked!
Only slightly more challenging than removing the dislocated thread was finding a replacement as Specialized dealers don't stock them and Specialized themselves advise you to ask your dealer. Hmmmm.
I ended up with the insides of a couple of Ritchey rear mech adjusters which work a treat.
So, is there a moral to the story? Yes, grease the buggers before they seize.
Ride safe