Cohort of British Auxiliaries on Hadrian\'s Wall

[Peroni]

Hamian archer impression. I've read your article on your group's site, do you have any useful pictorial references we could use?

The best pictorial references are in the article. The Trajan's Column depiction and the Housesteads archer.

there's also the gravestone of Tib. Iulius Abdes Pantera IIRC from Bingerbruck.

Also what do you think about the Hasta/Pilum issue?

Well, There appears to be evidence relating to one of the cohors voluntariorum cR using a parallel-sided, curved scutum. (Carol van Driel-Murray A shield cover from Roomberg - Cohors XV Voluntariorum cR)
Nearby, in the Corbulo ditch, the remains of a pilum were also found, suggesting that this Cohort, raised by Augustus, from Roman Citizens, had the same type of equipment as the legions. Possibly due to the status of a Citizen cohort. They certainly got the same pay as the legions thanks to the will of Augustus, so maybe it was also reflected in their equipment too.

There's a depiction on Trajan's Column of an auxiliary soldier carrying a curved scutum which could be either an artists honest mistake, or that it represents a soldier from a cohors scutata or Vol. cR unit.

I don't really see a problem with using a more Germanic sidearm in place of the pugio, but generally speaking, as we see in abundance from the Rhineland tombstones, that the auxilia were equipped with 'Roman' kit. Certainly in undress order, they look no different from the legionary soldiers in their appearance, which includes the pugio.

The alternative would be to go for an earlier 'Claudian invasion period' look, with slightly more irregular troop appearance with more native clothing and equipment.