This example below, which may or may not be at the British Museum (I found it on Pinterest, and reverse image search didn't bring up anything definitive. It could be a modern copy, but the bead quality and cut makes me doubt that), is what I based my knots on. Mine are definitely not perfect, but this was meant to be a quick project to get my feet wet again. Success! My feet are wet, and my goal is to remake this with better knots that are a little smaller. I think I also want to shoot more for the shape of the one above, with a completely closed neck.
One final example from the British Museum, an individual link that's 2.5 cm long. This one has less refinement, and is more like what I accomplished. I need more practice. Though this is the size I'd like to aim for next. My current ones are more like 4 cm, end to end.
My links are 20 gauge fine silver (all examples are gold), soldered into loops that were further formed into shape using a ring mandrel, round nose pliers, and my fingers. Each knot is soldered at 4 points. I chose not to solder the center points. I probably should have, but I melted quite a few of these, and decided to call them done with 4 points of contact connected. I would probably use 18 gauge wire next time.
Loops!
Rough forming.
The shape is kind of like a club, or almost a ping-pong paddle. I want to get a more defined neck with a more circular smaller end next time.