Saildrive Stuck in reverse

[hoaga]

Hello,
I have a Volvo MS25S saildrive (Volvo md2040 engine), and it is now stuck in reverse -- so I'm looking for ideas on how to fix it.
I'm in a pretty remote location in Fiji so access to a mechanic is unlikely at the moment. Though I can get to one before too long if necessary. (I've looked at the other couple of similar threads, but they pertained to a yanmar, and so far haven't been helpful).

I shifted into reverse rather quickly yesterday in order to try to avoid a mostly submerged buoy. The engine quit, and the transmission is stuck in reverse.
I've tried diving and working the prop back and forth, but I can't really budge it.
I've tried starting the engine even though it is stuck in gear, but the engine won't start.

Any ideas? I'm guessing I need to start taking things apart, but could use any ideas/guidance available. I'm mechanical, but haven't ever taken a transmission apart. I do have the manual and schematics on board.

Thanks,
Arthur