I'm trying to make a stylized chain (the hardware kind, not a bike chain or jewellery) in Inkscape. Initially I gave it a flat effect, and this was easy to achieve. For the O-shaped links, I used rectangles with the corner radius set to half the width (on the right in the image below), and for the ones you see side-on, just a single stroke with rounded caps, the same length as the rectangle.
But after trying out this design, I've found the chain links need a bit of depth to show their shape. The side-on ones are easy to do with a linear gradient, lighter at the top and darker at the bottom, and you can see below I've done one this way. The O-shaped ones are more of a problem, because a single gradient isn't enough. There needs to be a gradient on the two long edges similar to the one I already have, but there also needs to be a radial gradient going around the bends, so that the top edges of the bend are lighter and the underneath edges are darker. I can't work out how to fit all those requirements together and get a smooth result.
How can I achieve this effect in Inkscape? I'm not expecting it to be photorealistic, but I'd prefer a smooth gradient (to match the style of the rest of the image) rather than two-tone or something similar.