While I'd tell you that Technics dust cover hinges are shared across so many different models - the SL-1301 is an odd one. It's made up on the base piece (p/n: SFUM170-07) and the cover piece (SFAT170-01A). That setup, as far as I can tell, was only used on the 1301, 1401 and (I think) the 1501. We've gotten these hinges in the shop in the past but, unfortunately, we don't have any available right now.
Good luck with the hunt!