Hi Lisa,
you’re welcome 
Fine, please check and tell us what you need, you’re more safe buying at Bill because I’m just a private. I couldn’t even say that the shipping would be faster inside of Europe 
Short explanation for the seat pin: It is essential for preventing the seat of slipping (and turning) along the seat tube. But it is also very important that the clamps are tight; the seat pin alone can’t withstand the riders weight.
Best regards,
Chris