I have a 1977 W100. I can't find the sway bar end links anywhere. I found something that looks close, but is labeled for years post 1977. The one I found was marked as Mopar Replacement: 4036005 It doesn't have the fixed bottom cup near the eyelet like the broken one does in the photo.

 

The other day I was looking at aftermarket sway bars for my 86, and they also had stock-ish styled ends that are supposed to be stock replaceable. I’ll be right back.

EDIT:
okay, found the site and they have a whole kit, bar included that would fit your truck, and the hardware looks like probably the same kind stuff you saw with just loose washers on a bolt with bushings. But honestly I wouldn’t suspect that to be an issue, as long as bolt length, diameter and bushing sizes are correct/ fit with proper angles under load.

I could also give you the phone number of a huge NOS stockpile company for molar stuff and you could hit them up.

 

Yes please!

 

The link shown could be rebuilt with vulcanizing adhesive (about $10), rubber scrap from a radiator hose, and welding a new bolt on to the eye. Needs to be glued/vulcanized to keep the inner sleeve in the bushing from walking due to minor thrust loads between the bar and strut with the suspension movement. A standard universal prothane saddle bush and bracket (about $20) could be adapted with minor fab (to the new part, not the strut or bar).

My 85 didn't come with a sway bar so after looking for an original bar (found one with no parts for $150) and the cost of aftermarket at over $200, so I am in the process of adapting bars from other applications. Parts total is about $100 for front and rear but they are not bolt on as-is.