This is the frame of my CM2000, the suspension is 2 axle halfs, not a full axle. Northern tools sells the axle halfs. I would assume the only factor would be the angle that the arm is welded on. You could try calling CM directly for the replacement part.
I talked with Time Out (new owners of Cycle Mate). They have a suspension/hub/bearing set for $279 plus $20 shipping. They said the new design is one piece instead of two separate pieces. Now I need to decide if I want to spend $300 plus another $80 for tires on an 11 year old trailer that is worth maybe $600. Or do I put that money on a new/newer trailer.
If the current trailer serves you well and you are happy with it I wouldn't hesitate to go for it. Now if you are leaning towards another brand, type trailer I DUNNO. Gonna be hard to sell a trailer that needs work also.