Sorry, wouldn't have a clue, but if the replica prices are any indication, I'd say it's worth at least $200-$500 if it's as precision built as some of those I've looked at online for my Buffalo Classic for $125 and waaaay up!! A modern Marbles will cost $125 and up...I'd contact Marlbes and see if they can tell you more about it and give you a value on it. Take a pic of it and email it to them with an inquiry.
info@marblesoutdoors.com