All went smoothly thank you
Quality of 3D printing is good and it fits the standard 58mm Rancilio portafilter perfectly, but it must be forced onto the bottomless Rancillio portafilter (which must have a slightly larger outer diameter). Delivery was fairly quick. The main problem is that it does not allow tamping though the portafilter (for example like with the Breville portafilter), which means that the main (or only) use is to reduce spillage when adding coffee. However, because it must be removed before tamping, I find that the amount of spillage is similar with or without it. The shipping is expensive relative to the cost of the item, so not particularly good value. I sent the vendor an e-mail asking if it was OK to force it onto the bottomless portafilter (I was worried that it might break) and he did not reply.