Yup, when it comes to calfskin, the calves, themselves are only so big. When they are skinned, only a certain size diameter can be cut out of a single hide. And then they are stretched and shaved and scraped. So, it's quite a process to make a nice, consistent (as possible) calfskin drumhead in a larger diameter. And "slunk" heads are only going to be so big, too -can't get too large a diameter, there! *gasp* You WILL pay for that processing, nowadays! Can you imagine the smell working in a tannery? It must be quite a day of skinning fetal calves, hmm?
Yes, but the biggest a slunk skin would be would be for a 16" drum for a vintage marching snare. Slunk is only used as a snare side head remember? x-mas3