jgeratic,
So far, I haven't done a whole lotta digging, but I've only seen Adamson on the port side.
As far as the Teufelkopf, it seems that the switch in placement from under the canopy to the cowl took place sometime in mid-1940. I know the emblem was still under the canopy on some aircraft in March of that year. If it stayed there during the month of May, I dunno. Like I said, I haven't been able to dig too much before writing this.
But I do know that in autumn, 1940 there were aircraft with the emblem on the nose, so if you're going to do a BoB Emil, I'd say you'd be safe in putting it on the cowl.
I'll see what else I can dig up and maybe post some photos.
Fade to Black...