I've always liked the Ginger, but only have 1 left. I no longer have the model without wood base.
Every Ginger I've seen without wood base has the same round hole and locking door (which is often missing) in the mech base to empty the coins.
I've notice that on the ones with a wood base, Groetchen varied the size/shape of the opening in the mech base for coins to fall thru.
Mine is similar to yours, but less rounded on the one end; we both have what I believe to be remainder of locking tab when it was a round hole (photo below).
There is a Ginger currently on eBay with wood base which has a larger opening in the mech base and the tab has been cut away by the expanded opening.
The one on eBay also has the 4 screws as yours in bottom metal plate(mine does not), which I believe were simply for attaching 4 rubber bumper style feet.
My theory (developed just now);
Your Ginger is all original.
Ginger started out without the wood base and had the round access door on bottom of mech base plate.
They soon went to wood base to accommodate a lot more coins and expanded the round hole for coins to fall into base.
The hole got bigger since some coins still fell onto the mech base plate.
During the transition, they may very well have made some without the square locking door in the wood base metal bottom; coins would be emptied by removing the case and getting them out the same hole they fell thru.
Unfortunately, the guy who knows more about these than the rest of us combined is no longer with us (RIP Bill).