Park makes a freewheel tool that fits Maillard freewheels (FR-1), is this one not compatable with yours? Both Colorado Cyclist and Bike Nashbar sell this tool. If this one isn't compatable with your freewheel, I know a way to remove freewheels without a tool.
To remove a freewheel without a tool you need to dissasemble the freewheel and use a plumbing pipe wrench on the freewheel body. The cap on freewheels is reverse threaded, they usually have two indentations that you need a tool like the Park pin spanners to remove (they make several so you need to see which one will work). When you remove the cap there are many little bearings that might go flying (depending on how much grease is left in the freewheel). Remove the cap and dissasemble the freewheel with the wheel over a towel to catch the bearings if they do go flying. The exact count isn't absolutely criticle, but try to figure out how many of the bearings were on the inside and outside of the freewheel. Then dissasemble the pawl system. Most freewheels have two pawls on opposite sides held in place with a circular spring. After the pawls are removed you can use the pipe wrench to unscrew the freewheel body. It often helps to use a doorway, or wall area, for leverage. Put the wheel in the doorway so when you put reverse leverage on the freewheel body it wants to drive the wheel into the frame (wall). Place the pipe wrench on the freewheel's body in a way it won't damage the bearing races. You don't have to worry as much about the pawl seats as the races, but if you can avoid those too it can't hurt (although sometimes the pawl seats are needed to anchor the pipe wrench). You then apply the reverse pressure (as you probably know) and that will take it off. You might need to use a LOT OF PRESSURE, freewheels tend to get screwed on really tightly. Then after it's off put it back together before you forget how to do it.