Larry,
You didn't mention what type of impression your son does, so it is hard to say how period correct it would be. It would be more correct for a civilian impression than most military ones, for example, though it would be OK for a militia impression. It also would have been more common for a tradesman or artificer - even in the militia.
The fact it is made in a general period style with period materials makes it OK for a wide range of reasons, but it would be good if your son had a "period reason" for carrying it - even if it was because it was made by his father to last longer than a cloth or canvas bag.
Gus