Every once in a while, you can see one of these cameras up for auction on eBay. It is not really a Mamiya NC series camera, but for the die-hard collector these license models are also of interest. They usually don´t sell for a very high price (around US$ 50 to US$ 75).
The only difference to the Mamiya NC 1000 besides the printed model name is the lever for the self-timer which looks slightly different. The black version is called 1000 MXB (B = black) and the silver version is called 1000 MX.
I have no idea during which period these cameras were actually sold at Sears. In case somebody has some additional information on these cameras, please let me know and contact me via e-mail. Thank you.