Hang on a minute though. Isn't there a significant difference [diameter, locking lugs] between a AR pistol buffer tube and a AR rifle buffer tube? Did the pistol in question have a pistol or rifle BT? Because if it was a pistol BT then it wouldn't qualify as 'easily or readily convertible', correct?
Not an AR.
Difference between a SP-89 and a SP-89 with stock is removing two pins, swapping the backplate for a stock, and reinserting them. Total 30s of assembly time (and the required tax stamp and all that jazz, for the nitpickers that will appear if I don't add it).