Re: DW 5000 replacement parts
My local hardware stores have those master link retainer clips in their fastener cabinets. I believe it's a #25.
If you have an Ace Hardware in your town, they may very well have it.
My local hardware store is quite used to me showing up lugging pedals, tom arms, cymbal tilters, lugs, etc. to replace missing pieces.
They should at least be able to replace the cap nut on your Delta hinge. Just bring the pedal down to the hardware store and show them what you're looking for.
The kind of hardware store you need is an Ace, TrueValue, DoItBest, or similar.
It sounds like your pedal is taking a beating, so this would be a good time to wipe it down with a microfiber cloth and drop some TriFlow or other teflon oil into that hinge bearing and the axle bearings. Dirt is abrasive, and you'll get more life from the pedal if it's kept clean.