Hello Henk,
There is no right or wrong way of mounting in my opinion, I would not remove an original ribbon, as worn by a recipient, but, court mounting is done so as to avoid contact wear, in an ideal world, original silk ribbon would be used, but, this is now much harder to actually do with the passage of time and the problem of finding it in any quantity.
I knew a collector in Johannesburg who once had the finest Kimberley collection in the world, but, he actually court mounted his entire collection on polyester ribbon!
Kind regards Frank