Your best bet might be to contact Sears in Chicago. Ask for their 'Reasearch Department'. They have such a department for their Kit Houses. Perhaps they might have something for their hardware.
DUNLAP INDUSTRIAL HARDWARE, EVERETT WA 98201 might be the folks that contributed to the saw. It couldn't hurt to ask. And if they aren't the ones, see if they know which Dunlap it is. My best to ya and hope this helps.