The method is described in Amazon Kindle book "ImageSearch for HS classification"
*Movie is here. Amazon By country> US|UK|DE|FR|ES|IT|NL|JP|BR|CA|MX|AU|IN
“part” of an article is something necessary to the completion of that article. It is an integral, constituent, or component part, without which the article to which it is to be joined, could not function as such article.
“accessory” is, subsidiary devices used in connection with the machines, such as interchangeable devices which modify the machine so that it can perform a wider range of operations; devices to increase precision; devices which perform a particular service relative to the main function of the machine.
Source: EN Heading 8466 (B)