Ever regretted selling a pen? This is one I would love to have back. It's a fully marked English-made Esterbrook Relief button-filler, the size of a streamlined Duofold Senior, basically a rebranded version of a Conway Stewart Duro. I found it in England in the mid-1990s at an outdoor antiques fair, and I've never seen nor heard of another one since. These are the only pictures I have of it, taken back in pre-digital days.