Yes, the NGM stands for Nested Grid Model. Back in the '80's when I first started using them, there was the LFM and the NGM.
LFM, Limited Fine Mesh
The only thing limited about it was its ability to forecast qpf. The rule of thumb was to halve what it showed. It had major convective feedback problems, and left-track bias, probably due to convective feedback. It has no role in today's forecasting, hence, you can't find it. That's not to say it missed every forecast, but its biases were longer than I am tall it seems.

NGM:
That was considered the stronger of the 2 models then, and it was. By today's standards, it gets little press due to the ETA, GFS, and the new sets like MM5, etc.
It had a problem with cold-air damming situations if memory serves me correctly, and I think it had a right-track bias.
When i was in college in 1987, I started getting the 3 day MRF via facsimili software. Then, that was like a breakthrough.
I provide this as a frame of reference to where we are, from where we've been. Using those models back then really increases my appreciation for those of today in spite of their flaws.
For the record, I almost never look at the NGM anymore.