For the higher numbered/more recent maps, I think those are placeholders until they get (re-)printed. In response to a question I posted on CSW, Chas noted that individual map printing is generally tied to larger jobs for cost purposes, so those of us looking for individual maps will need to check the MMP site periodically to see which ones are back in stock. If there is an ASL product that includes ASLSK-style maps that gets printed, there's probably a decent chance that some of the individual maps would be included in the print run. Am hoping by the end of the year, most of the out-of-stock maps will be available at some point.