Hmm...I used to make concept designs for Monopoly boards at my old school; let's see if I can help with ideas.
Well, you could easily make it so that the game represents a hypothetical GOF/S journey; make "Go" the Great Valley, and then have every property be a location in the Mysterious Beyond. The playing pieces should all be the Gang of Seven; Littlefoot, Cera, Ducky, Petrie, Spike, Ruby and Chomper, and as a result, each cycle of the board becomes leaving the Great Valley, going on an adventure through the Mysterious Beyond, and then returning home...before repeating the adventure again! "Go To Jail" should be "Earthshake", and "Jail" itself should be a picture of the unconcious Sharptooth in the divide. "Free Parking"...well, let's come back to that. Houses and Hotels...probably the best thing for them to be would be Treestar trees and Treesweet trees. Treestars would have to be the money. Chance and Community Chest...darn, I'm not sure. I suppose you could use these to reference the songs; perhaps one is called "Adventuring" and has a profile shot of all the GOS walking in a line to represent it. I couldn't help but think that picture of Littlefoot seeing his reflection in the treestar's dew would make a good picture, too.
Obviously, all of the properties should be major locations, as opposed to things like characters or objects - I remember seeing a Monopoly board based off Myst (which is all about logic puzzles in amazingly beautiful worlds) where half the locations were objects from the series, as opposed to the actual locations you get to visit. Instead, they should be referenced in the Chance and Community Chest cards. For example, the card "Advance To Illinois Avenue" could be something like "The Rainbowfaces show you a shortcut to [random location]" (sorry, couldn't think of a better example on short notice).
Each property should have a picture of the location on it, and then an image of a prominent figure who lives in that area next to it. For instance, the Land of Mists could be a property, and have Tickles or Ichy & Dil on it. This could also be used to give places names when there isn't an official name for them; placing Archie beside a picture of the caverns from the fourth film would allow you to call them "Archie's Caverns". Course, you should shy away from placing any of the playable characters on a piece; rather than show Chomper next to the "Mysterious Island", show Elsie, or one of Chomper's Parents. Each location should have some vague link to its neighbours; either they're all dangerous or safe, they're all in the same area, they were all visited in the same film, etc.
The Railroads could be significant natural formations; "The Rock That Looks Like A Longneck", "Saurus Rock", "Threehorn Peak" and...something else. Failing that, the first two could be the utilities, and "Threehorn Peak" could be a location (with Rinkus and Sierra on it).
As for other locations...well, how many significant locations outside the Great Valley could be used? I haven't seen the TV series yet, so you'll have to help me here...
*The Tree Grove (LBT I, where the longnecks eat all the green food)
*The Rock That Looks Like A Longneck (LBT I)
*The Mountains That Burn (LBT I)
*The Lake (LBT I, where Sharptooth gets killed)
*The Trapped Water (LBT III, where the meteorites blocked off the Thundering Falls)
*Archie's Caves (LBT IV)
*The Land of Mists (LBT IV)
*The Desert (LBT V)
*The Mysterious Island (LBT V)
*The Smaller Valley (LBT VI, housing Saurus Rock - which should be located nearby)
*Saurus Rock (LBT VI)
*Threehorn Peak (LBT VII)
*The Hot Pools (LBT VIII)
*Big Water (LBT IX, with Mo)
*The Sun Crater (LBT X, where the Longnecks gather)
*Bron's Valley (okay, this one hasn't appeared, but it'd be a way to work him in)
*The Caverns (LBT XI, where the Tinysauruses live)
*Berry Valley (LBT XIII)
Alternatively, you could draw a picture on the central area of the board of the Mysterious Beyond and the Great Valley, and divide the board so that a certain area is the Great Valley, and the rest is the Mysterious Beyond (perhaps the purple and dark blue properties are the Great Valley?). Course, with that in mind, it could make sense to make "Free Parking" into "Big Water".
By the way, you should consider working in some of the older elements of Monopoly that don't exist in the newer versions. For instance, did you know there's a bunch of Chance and Community Chest cards that have been taken out? Some are fairly simple (It's Your Birthday, Collect $10 From Each Player), some are kind of odd (Drunk In Charge, Pay $20/We're Off The Gold Standard, Collect $50) and some are just cruel (Collect 10% Of Every Player's Money)! There was even an expansion pack called Stock Exchange that replaced Free Parking with an extra square that let you buy stocks. Whenever you landed on them, you got money depending on how many stocks you owned (although in practice, I found this worked better if you made it that you could buy stock and earn money whenever you landed on Chance or Community Chest).
