I believe the DSS supplied version is or was UK made by Motad, and looks the same as OE but the headers were all separate and of course single skinned, though the chrome does look good.
I bought a set of these direct from the manufacturer after seeing their post on here. They were surplus stock supposedly but as I haven't yet tried to fit them I am not certain they will go on easily
... My genuine collector was supplied (around 2010 ish) with two non-OE single skin headers, all from Silvers, and they needed flexing to fit up as I think they were a few degrees out on the crucial bends. Roll on a couple of years and I sourced two genuine unused headers , one from CMS was perfect the other old stock and needed re-chroming at £80 !!
Plan is to fit the replica set sometime then mothball the genuine system while it is still pristine !
Wish I had the Yoshimura off my original F2 .... great noise