This was bugging me, so I did a bit of research. The Onkyo SM 20 appears to be one of two (SM20 and SM10) table top music systems Onkyo produced back in the day, as they say. They came complete with speakers and a receiver and in the same cabinet as the receiver was installed a turntable. I have not been able to identify the turntable manufacturer, which may not have been Onkyo. Kenwood, KLH, Sony and others made similar systems.
https://www.hifishark.com/search?q=onkyo+model+20If you are trying to replace that bent stylus a new cartridge should be available, maybe even just the stylus. As long as the replacements dimensions are the same, it should fit and work. The only unknown is if the cart is magnetic, or a budget ceramic model