About the head i thought the same idea that Gordons head is quite fine but also DID WW2 Gerenals Guderian or Keitel with blue grey eyes, moustache, and blond hair would be other head options.
Those would be my options that could match quite well as G. Antoc Merrick. And some repaint touches if...
I thought about gloves. I got TFA Han Solo and Luke Snowspeeder pilot SSC. Looking forward and pics of G. Antoc Merrick i noted he wears the same as Hoth Troopers (Luke, Han Solo, officers and troopers) worn in ESB in the battle of Planet Hoth. So i bought those that Luke ESB SS pilot wears that...
Outstanding blue squadron pilot of Rogue One. I tnought the same idea and asked to Enaud about it. I got gloves from Luke Snowdpeeder pilot SSC and helmet likewise. Awesome look