I am on the other side of the country.
None of the work is really gun work. It doesn't require a gun person until you take it out to shoot it. So, if any other parent/guardian can make sure they don't sand too much or try sniffing the wood finish,....
Assuming older boys which can be trusted, they could probably do this project on their own.
The real issue IMHO is the cost and you have to have a place setup to let the parts sit and dry.