Gravity Research Brakes? -- Help Identify Please

[abailcb]

Got a couple of boxes of odds and ends with a frame I bought last week. These brakes were in a bag along with random pieces and parts. There is a Kona P2 fork in the lot, so I thought they might be Curve. After taking them out of the bag I could see they def weren't Curve. At first I thought Grafton, but after removing the springs I found "USA" on one arm and "GR" on the other. The blue adjusters were on the arms, but I found the other set in a different bag of parts also.

I'm having little luck finding much on these. Can anyone confirm for sure that they're Gravity Research? which adjusters are correct?

Thanks.

 

[slimjoe]

That's definately a very early say 91 raw finish Gravity Research brake. The silver spring holders look right. The blue ones look like later Rim Crusher type. Pencil me in if you ever part with them