Hi,
it is possible you have a 1.5, but I think they haven't produced much 1.5 types.
There are rumours that 1.6 xboxes only work with original memory devices.
Suppose it is like that, you could try to wire a male USB connector to the pcb that was in the memory device housing. If you connect it to your pc, you should be able to put the gamesave on it with the xplorer360 program that is capable to handle fatx partitions.
On Ebay, you can find a cable with a game controller plug on one side and a female USB on the other side. They cost something like 3 euro. Using such a cable, you can plug your USB stick directly in a gameport of the xbox. I can't guarantee it will work, but I know the connections are right.
If you know someone with a modded xbox, you can ask him to put the gamesave on the memory device with his modded xbox. You can use an original memory device, and you don't need to solder.
regards.