I'll help out how I can. Send me a message.
Otherwise, I have one idea (dont know if it's a good idea or not).
Educate them on the classic coins in the standard denominations.
IHC, Wheat, Buffalo, Mercurys, <65 quarters, Franklins, etc.
Instruct them to keep their eyes out for older coins (actually "hunt" for them).
Each time they find one, they submit it to you for cataloging and storage in the Pack's Collection.
Label each coin's value.
You could establish a goal, merits, a game, or competition.
I think this engages them in a more active way.
Jim (two merit badges short of Eagle Scout -- boo hoo -- I was too chicken back then to publicly speak for the last two merit badges)