I found a used compton bridge, that has 2" string space, but my 5120 has 2 and 1/16" spacing on the current/stock bridge.

Will the 2" string space make noticeable difference, or should I just pay double, and get a new compton that has the 2 and 1/16" string spacing?

For radius, it seems to vary from guitar to guitar, some are 9.5", some are 12", gretsch are notoriously inconsistent with radii.. you'll need to measure using this: http://www.pickguardian.com/pickguardian/Images/Pickguardian%20Neck%20Radius%20Gauges.pdf

The string spacing will slightly affect how the strings sit over the pole pieces, bit given it's only 1/16" it shouldn't cause too many problems, I'd be more worried about the radius. Also, have you confirmed the post spacing will fit your bridge base?

Good luck, hope you're enjoying your compton in no time!

I have a 2" Compton on my 5120. I don't notice a difference. That's 1/16" spread across the 5 gaps between the strings or .0125" per gap. And only at the bridge. That's the thickness of 4 sheets of printer paper. At the 12th fret it would be .00625" per gap.

I have a 2" Compton on my 5120. I don't notice a difference. That's 1/16" spread across the 5 gaps between the strings or .0125" per gap. And only at the bridge. That's the thickness of 4 sheets of printer paper. At the 12th fret it would be .00625" per gap.

Good to know, thanks. I may have to get that used compton.
Did you install the compton on your 5120.
Do you like it better than what it had?