Over barrel mods are out..... the barrel on the Dark is too short...
Alison at Wildcat says they are developing something, but due to current climate this isn't going to be quick...
Ase don't do one, Tukka replied very quickly on that.... SilencerCo won't supply the UK, but do offer some options for US customers....
Brugger and Thomet will modify one of their Starlite Suppressors, but at some cost (£500 ish)..... these are somewhat wider than the standard front sight post and will require an optic to clear the can....
ETA: Jacksons have nothing for the 45/70