accessories added in second time: should they be certified? how?

[reggio]

hello, would you tell me how you should behave about the additional components / accessories?

I mean, I sold a roller coaster, after 6 months they ask me an additional side bank and a lower cover: should I correct these new accessories with a certificate / declaration c?

How should I behave in case the original roller was sold as a machine?
How should I behave in case the original roller was sold as a machine?

 

[pollo]

but a roller coaster can be qm?

 

[reggio]

but a roller coaster can be qm?

of machine or almost machine is discussed many times (personally) without being able to draw a clear and satisfactory definition, in any case, to return to the question above,

Yes, we say that the roller conveyor can be machine (e.g. motorized roller conveyor)
Yes, we say that the roller can be almost machine (e.g. gravity roller)

... or to pleasure the roller can become conveyor belt...

how should you behave regarding additional components / accessories in both cases?