Yes, the component sell by Marco will fit perfect for your NGG.
There is a little mistake on Marco Website, this part in labelled U22 instead of G10, but it's a minor error, the chip is really a G10 for WPC-95 pinballs.
On both WPC-S and WPC-95 pinballs, Williams/Bally use a PIC µ-controler (that is a bit more complex than a simple EPROM). The name of the chip is U22 for WPC-S and G10 for WPC-95, but it's basically the same. The model of pinball is encrypted in this chip (561 for a NGG) and you should use the same number as the EPROM of the CPU board (ie, if you change the EPROM for Cirqus Voltaire - model 562, then you need to install the matching Security PIC with 562 ident).
Only the model is checked, not the full serial number, nor the version of the EPROM.
So this G10 for NGG will work with all versions.
At startup, your pinball display the full serial number on dot matrix : something like 561 123456 12345 (where 123456 12345 is your serial number, printed on labels inside cabinet and on the G10 chip).
When replacing the U22/G10 Security Pic, you loose your original serial number. All replacement chips are encoded with a generic number like 999999 99999 or something similar. If you don't care about your serial number, then the chip from Marco is perfect.
But some pinball's collectors want to keep their serial number, so we (at Flipprojets) provide an on-demand service, and program chips with the serial you want. So there is a solution if you absolutly want to keep your original serial number. But if you don't care about it, then the Marco solution is fine for you.