I actually did that this weekend. You can JB weld it and it will hold, or melt the plastic down and it will bond itself. I went with the JB weld and so far so good.
There are not markings on the housings but from visually checking it they seem to be HDPE. I don't know if it would be ABS, a complex shape like that would be difficult to fill with ABS since the housings are injection molded.