Hello fellow Canadian and welcome to the forum.
I'm also a REV2 owner, and Rush fan from the era you talk about, and most of the sounds of the synths in those days comes from Oberheim, Minimoog, and then later on a lot of PPG stuff.
Some of those patches are impossible to replicate on the REV2, due to the peculiar way the LFOs work. I'm talking about the sounds of "Camera Eye". It was done on a custom Oberheim 8 Voice that Geddy Lee used. I've recreated it on the Behringer DeepMind 12 quite easily, but the REV2 is incapable of it.
Moreover, the overall tone of the REV2 is not very "Oberheim", even with the filter set to 12 db mode. The DM12 gets a lot closer to it IMHO. The OB6 can do a lot of the sounds that were used on those albums, even though it's missing a couple of voices of polyphony.
Here's what the DM12 sounds like on that particular patch.
https://soundcloud.com/thealien666/camera-eye-deepmind-12As hard as I could try, I could not get that on the REV2.
The OB6 can also do that, but requires two hand manipulation to raise the filter modulation, as heard here:
https://soundcloud.com/thealien666/ob6-camera-eyeThe famous Tom Sawyer intro patch can be faithfully done on the REV2 however, since it requires the ability to disconnect the keyboard control from the oscillators and control the filters cutoff frequencies with full keyboard tracking, as heard here (thanks to infindebula on YouTube for an excellent tutorial on how to correctly program it on the OB6, but can be also programmed in this way on the REV2 but it sounds better on the OB6):