I have December 1947 and have been looking for a 1948 for twenty five years with no luck. Skennerton's first Lee book had the last listed as 10/47 based on contract information and one that is now in my collection. I later found 12/47 and subsequent literature was updated to reflect that find. Certainly this was at the end of the program and the plants would only have been paid for what they could get out the door, floor sweepings included. Possibly there was some 1948 construction using 1947 dated receivers.