Need a new aerator/shutoff valve for my livewell

[SixStringHack]

Anyone know of any dealers or marine stores in the Ottawa - Sharbot Lake corridor that carry a lot of parts for live wells?

One of my aerator/shutoff valves is stuck open and the handle is stripped so ideally I'd like to just replace that one part. It screws on with a 1/2 inch threaded connection that seems to be non-standard when compared with 1/2 inch threaded stuff available at Home Depot. I think my connection is coarser (fewer threads) than standard plumbing stuff.

Replacing all of the plastic bits back to the hose is possible, but it looks like a real pain to get at and my scraped-up arms have just healed after working on my fuel anti-siphon valve a few weeks ago. The boat is a 2004 Lowe and Orleans Boat World doesn't stock specific parts for it. The generic aerator/shutoff that OBW carries has the wrong thread size, it is too fine.