Well, I picked up a Spong #3 this week for $40, in good condition (still with most of the sticker and the gold lettering/trim) but lacking the grind tray. Opened it up and it was pretty clean inside, gave it a wire-brushing anyway then ground through 100gm of coffee. I've adjusted it to suit filter brewing (aeropress/ccd, etc) and can grind out 16gms in about 24 cranks of the handle. The burr is massive, like 4". The output is nice, fairly consistent, especially for the age of these things!

