[Runequest] Grappling with grapple rules

[royce at efn.org]

Greetings, comrades,

Situation:
   In my off-&-on effort at a campaign, furtively pursued when time
permits, I was writing up some NPC's.  One is supposed to be a
wrestling expert.  Looking up the RQ3 rules, I quickly realized that I
hadn't previously thought the rules through.

RQ3 Rules Comprehension:
   Assume one human male character grapples another.  The successful
grappler rolls a hit location.  On the following melee round, if the
grappler succeeds again, he may either throw his opponent or immobilize
the hit location.
   Correct?

Immobilize Locations Other Than Limbs:
   What if the grappler had grappled the head, chest, or abdomen?  Are
there precedences for attempts to immobilize these locations?  Or did
the rules writers assume a throw, instead?

My Own Speculations:
   If no precedences exist, I had a couple of simple thoughts.  (Nothing
clever, mind you.)
   For head immobilization, perhaps the GM could rule it as choking.  Then
RQ3's established rules for asphyxiation would apply.  A simple
solution.
   For torso immobilizations, perhaps the GM could allow the grappler to
wrestle his opponent to the ground.  This might be a step toward a
third melee round of grappling skill rolls, the success of which could
be the immobilization of the opponent's body -- pinned to the ground.

Feedback:
   If my speculative ideas are flawed, please feel free to say so.  I am
open to constructive criticism.  Who knows -- I might even learn
something in the process.  :-)

   Sincerely,
Asher