If it has a place for the stacker thingy, I can send you my extra one with the spring (slightly bent).
Here are some pictures of my 2nd deck. I transfered some guts from one to the other. But I found that one part was not transferable because on my 1st deck the part has a pin that fits into a hole, but on the second deck, there is a pin where the hole is and the part fits over the pin and rotates on the pin as an axis. To fix this, I'd have to take off a lot more parts... which I cannot do because the screw in the picture doesn't like to loosen... and I'm not sure what kind of can of worms I'd be opening if I did remove it.
Help? Why are two identical models built with a different attachment like that? Everything else looks identical.