Working DayStar Digital PowerCache 50MHz accelerator. Used/tested this on a Mac IIci. It doesn't have the FPU (available for around ~$20 on eBay), but has the 68030-50MHz CPU (see pictures).
http://picasaweb.google.com/simplepractices/FSLowEndMac#5376807079309607634
http://picasaweb.google.com/simplepractices/FSLowEndMac#5376807083435608578
Based on recent prices at eBay, I'm selling this for $50 shipped to the lower 48.