That'll teach him not to steal! 
(or at least, not to get caught - perhaps a more important lesson!) 8)
If it was part of his Essential Nature, then he has suddenly become an essentially* different person than he had been before the amputation. I'm gonna guess that's not the case. 'nuff said.
(* as in "at his very essence")
By the Guidelines, both "Restore a Lost Limb" and "Heal a Heavy Wound" are Base Level 25. That implies that those are different effects. The CrCo 40 Ritual "Incantation of the Body Made Whole" specifically states that it does not "heal such damage as missing limbs".
I would read that as not making a distinction between a long-lost limb, and a recently severed one. If the hand was "almost completely amputated", or "hanging merely by skin", then, magically, the whole is still one, and "healing" can occur. But once they are separated, that would require a different magic.
The Base 35 Effect uses the phrase "Heal all Damage" - the term "damage" here is, I'd suggest, a game mechanic (see p tables 179) - it is not a spell that perfects a body, removing old scars and such (which is a different use of "damage", in a general, casual sense, but not covered by this spell). Nor would it "Restore all Lost Limbs" - that would be a different (and unlisted) Base 35 effect.
(And, realistically, the word "healing" usually does not encompass "reattaching", not in this context.)
Hey, it's still reparable, and it'll make a great story! (And they can call you "Lefty" now!)