I don't know, given the legs do come off, it's kind of hard for me to believe anyone is going to pay you the cost of the entire piano for two legs. That just doesn't even seem credible. It would be as if someone damaged a tire to your car and you wanted them to replace the entire car.
On the one hand, what you're saying makes sense. But on the other hand, piano legs are not car tires, and you can't just go and get a replacement set that's an exact match.
If the responsibility is to present the customer with her piano, made whole, and there are not replacement legs available that match, then you can go down the rabbit hole: well, you have to get new legs made, special order. That'll take time and money. And then the finish doesn't match, so then they'll have to refinish the entire piano. That'll take more time and money. So they'll need to provide her with a temporary instrument while the piano is being repair. At some point, it becomes cheaper and logistically easier to just say that the entire instrument must be replaced. This might sound crazy, but the fact remains that a grand piano without legs is not a usable instrument, and the moving company is responsible for that problem. It also of course depends on what level of responsibility the moving company assumes.
Having said that all of that, I would imagine she'll be able to find some legs somehow.
Your piano is not a parlor grand, which is longer than 6'. I think that commenter presumed 175 was the length of the piano, not the model number. If it's 5 to 5.5" it is a baby grand.
That was me (who commenter about calling it a parlor grand). The OP has a Weber W175, or WG175, both of which are 5'9" (or 175cm). It is the case that not all grand piano model numbers refer to the piano's length, but many (perhaps more so than not?) do, and this one does as well.
As to how to describe that length, there seems to be some disagreement, but baby grands are usually anything less than 5'3" or 5'5" (depending on who you ask), and parlor grands are usually said to be 5'9" and up, hence my suggestion that she not call it a baby grand.