Try this!
: :
http://www.dhc3otter.com/310.htm
Master list...
http://www.dhc3otter.com/masterconstructionlist.htm
This N21PG Reg is no longer valid for this airplane...hmmm wonder where she is now?
UPDATE...Ah ha! Found her! She's a turbine machine now.
http://www.airport-data.com/aircraft/N49AW.html