A few questions from a beginner

[Robert Vermaat]

Robert I was thinking more in terms of the actual Roman soldiers doing this, although many modern groups ask for donations. In Roman times you would have been the local constabulary and if you read some of the documents from Egypt soldiers adding their own cut to the local taxes is a matter of course. Often this is done on demand from the soldier. So anyone who paid a road tax to go past your turret would also have to give you personally something or else! This practice was so common it appears in local business accounts.

The surviving late Roman helmets are all silvered or gilded are they not?

Agreed with both but the latter has no relation to the former - helmets were manufactured and gilded by the state (by the barbaricarii in the state fabricae) and had nothing to do with the wealth of the soldier.