Brass Knuckle Bruiser

[NoJuice]

A few questions.

Tike Myson, at the start of his career, has brawler and a pair of brass knuckes. When punching with these knuckles, does he inflict str+d4 damage or str+d6 damage?
Tike Myson, at the height of his career, has brawler, bruiser, martial artist, and martial warrior but only has d8 strength. Does he inflict d8+d10 or 2d8 damage with a barehanded punch?
Even if brass knuckles do not stack, can Tike Myson wear silver knuckles in order to punch werewolves to death with his "unarmed" damage?

[PEGRon]

Tike Myson, at the start of his career, has brawler and a pair of brass knuckes. When punching with these knuckles, does he inflict str+d4 damage or str+d6 damage?

Str+d4

Tike Myson, at the height of his career, has brawler, bruiser, martial artist, and martial warrior but only has d8 strength. Does he inflict d8+d10 or 2d8 damage with a barehanded punch?

d8+d10

Even if brass knuckles do not stack, can Tike Myson wear silver knuckles in order to punch werewolves to death with his "unarmed" damage?

This is a GM/Table call, but since the werewolf is getting hit with silver, despite the "stacking" issue, I'd allow it.