Yeah, they most certainly made 630's without a CD-ROM drive, in fact I'd imagine that most 630's you see these days are probably CD-less 630's that have had CD-ROM drives retrofitted to them. Basically, they used the exact same bezel as a 630CD, although a blanking plate was installed in the hole where the tray comes out, pretty much the same as the blanking plates installed on car dashboards for features that are not installed on that model.

In fact, that 630 in the photo in that wiki article appears to have no CD-ROM drive, and instead has said blanking plate installed. Though Dana's photo is better. Basically, they use the exact same bezel, so that all you need to install a CD-ROM drive in a CD-less 630 is the drive itself, the sled, and the power/SCSI and audio connectors that go at the back and connect into the wiring loom. There's some clips on the back of the blanking panel on the front, which you simply press down on, and the blanking panel pops out the front, and the bezel can go back on.