Last night, I picked up an No. 1 MkIII SMLE that had been sporterized.  In the process of getting chopped and redone, at some point the socket for the stock had its markings ground off.  I'd like to get the stamps redone, as I've always thought that SMLE sporters were a cool looking rifle, but they don't look right without the markings on the band.  

Yes, I know it will be more expensive than most sane people would think it's worth, and for a sporter it really isn't worth the time or money, but ––- does anyone have any idea where (or if) I might be able to find someone who has or could make the British ordnance stamps, and could re-strike the markings?

having ordnance stamps made would cost more than the rifle.  I would recommed you check with Orion Engraving.

http://www.orion-arms.com/new/

No such luck, apparently they aren't able to go over existing stamps/engraving.