Has he tried coastal rides. They deal in all sorts of s/h volvo stuff.
Failing that classic volvo forums.
Boats and outboards often have old volvos going cheap.
Is he after a complete engine with ancilliaries or just some parts?
The AQ 130 was the B20 block coupled with a 270 sterndrive. (Overbored pushrod engine from the P1800 with twin carbs)
The 200 drive is earlier than the 270.
What's the boat?
http://www.boatsandoutboards.com/view/PAA7754