I agree with the agreement, I believe they're subtly different rather than fully compatible clones. I had a heck of a time finding a Galaxy hop unit, and when I got a Jing Gong one (well, two actually) that looked identical, they were fractions-of-a-millimetre different, enough that I had to do some tweaking to fix the feeding and air seal.
What's up with the one you have? There's not much that can't be bodged with JB Weld or even a dab of hot melt glue.