Not sure about the OP's frame details, but the disc nexus will be spaced at 135mm, and being that this thread was originally posted in the FGSS forum, i bet there's gonna be 15mm's worth of discrepancy between the hub and the frame. He could spread the frame, or he could try to swap out those dooky-fat jam nuts for something slimmer**.... or, some combo of both. Personally, I think mconlux is spot-on in recommending the Sturmey-Archer; those things can be spaced down to less than 110mm OLD on some of the no-brake versions. Cost less, too.
**Not too sure of the Nexus axle threading, but google suggests it's 3/8x26tpi.... I found some slim 3/8"x24tpi jam nuts for a few cents at the local hardware; not sure if 26tpi is as easily sourced.... I mean, I got some in my basement, but....