They are usually good to go, however I have been disappointed at the number of low quality Bailey parts showing up in their offerings. Often I think the product descriptions are vague or downright wrong.
In August I bought an FBI UMP lower from them that was labeled all German, a few weeks after my purchase they changed the description (but kept the same URL and product number, in fact most of the reciews on the page are of the German part) to say it was a US/German part with US parts being made by GSG9. I was specifically buying from them because it was an all German part for an all German USC/UMP.
That lower (https://www.hkparts.net/shop/pc/German-US-Made-Safe-Semi-UMP-Lower-2-Position-193p590.htm) has been nothing but trouble. It's weak mag release spring drops mags on accident constantly and it's trigger stops resetting after firing a magazine.
I buy from HKparts because they have stuff that nobody else has and I have confidence it will be genuine HK. This experience had ruined that. I called and they argued with me and stated that the discription was correct when I purchased it. After discussing it with her supervisor, the CS rep backed off that claim and offered to knock the price down to what the US made part is selling for. $30 cheaper for a garbage product, and although the price has been changed on my order history it has never been reflected on my Visa statement.
Long story short, make sure you know what they are selling you. They can be vague or flat out wrong on parts description/origin.