Question about odd fit of AP parts

I just a few hours ago got my very first AP, but her lower torso and bust don't seem to fit properly into each other.
She has the C lower torso (soft skin) and C-1 Bust (most likely not soft skin) and the lower torso does not fit into the upper without forcing it.
I hope the image works.
A is parts not connected, you can see how the bottom is about the same width as the upper as well as how it had been slightly deformed.
B is showing how big the bottom part is, I can stuff the bust into the lower torso without even trying.
C is how the lower torso looks when the bust is put on. The back has a large cavern, where the vinyl fold in on itself to fit inside the smaller piece.


I assume this is not how they are normally supposed to fit, and I don't know if there is something I can do to 'fix' this

 

What AP did you bought? The C1 bust is her original one or something you bought for replacing the one she came with?

 

I own both a soft and a not-soft skin C-1 bust and there are definitely differences, in particular in how wide is the bottom opening.

The non-soft one is narrower than the soft skin one and when I use it on the soft skin H bottom I have, I also got a C situation. Not a problem for me, however.

 

I don't know if there's a way to fix this, maybe buying a non-soft C lower torso or a soft C-1 bust, but that's not a solution...

I would not risk to trim the parts either...

I got her secondhand and her paperwork says she's Rin, but as far as I know she has had a few owners before me so someone somewhere down the line must have switched parts as she came to me with this bust. (she is supposed to be F upper and non-soft skin C lower according to her paperwork)

But it's good to know that it seems to be a thing caused by the combination of soft skin and not soft skin, and not some weird warping. I was planning on getting her a different bust in the future so I will keep in mind that soft skin might be the best to use

By the way... the other day I had the same fitting "problem" with a soft skin G bust on a soft skin H bottom.

It's common.

 

You can see the squeezed back even in the promotional and official photos:

Quote

I've noticed that the back actually looks similar on photo A (in its natural shape?) and photo C. I've had a similar issue - exchanged bust H3 for G at H torso, and had to squeeze the vinyl and work it a bit to put it on (the hole for the bust H3 compared to G is gigantic). The movement range seems fine, however, so I left it on (if anyone knows if this is a supremely bad idea, please let us know).