Special wear parts for insider

The quick delivery, the price and the business idea who I liked. Where do you get such special wear parts? What I did not like is this: all the small parts are partially loose in a big bag. Then I have a content list with the number and name (material and dimensions for the seals would be helpful) the delivered parts missing. This would be quite useful to check if all parts were delivered and what they are intended. A Self-Made-Man has finally not automatically an all-round knowledge ...

Best regards