So I've recently (two months ago) purchased a Silvia+Rocky setup from my girlfriend's dad, and have nothing but happiness from it. The one issue is the tamper. He had a nice heavy tamper which he said had been sold online as 58mm. It's got lots of room in the double basket, though, and measures with calipers at 56.5mm.

So, the question: is this an acceptable clearance, or should I look for a larger one? And if so, does anyone with a Silvia have recommendations? I don't want to be stuck with another 56mm tamper sold as 58mm.

acceptable.