My mom's overlocker had this piece (which holds the thread bar up), and it broke. This worked as a replacement. 

I recommend you support it if printing in resin, as the bar channels might otherwise fill up.

I drilled a small hole through both (after aligning the channels) and used the existing broken part's screw to tap the thread. You could glue them together, but I like the idea of being able to iterate on the design if it doesn't work out.