For discontinued items, you can check Ebay and Etsy. You can also post a request on the "In Search Of..." forum of this board:
http://www.quiltingboard.com/search-f19/
I know how it is when you are used to a specific tool that is discontinued & you wished you had bought several of! I really like my teal and purple KAI 45MM rotary cutter from the 90's. There's a plastic part that wears out. I brought it to a show and the KAI representative just laughed & laughed. No replacement parts. I have found several, however on line using the resources above. good luck!