Hey there Rat & Marko,
It's 4 years after your post, but I stumbled upon it and want to offer my congratulations. I made 3 or 4 serious attempts on this route from 2013-2015 or so, and chatted with a few other people about it including Jim Nelson. Nobody knew of any serious attempt, let alone a successful ascent. And it's a damn hard mixed climb.
I think you can safely assume yours was the FA.
The earliest reference is a Mountaineers report quoted in the Becky guide. I actually went down to the Mountaineers Library and looked up the original report at some point. It wasn't helpful.
It's certainly been looked at a million times, but on my attempts (and on one summer scouting trip) I never saw any gear or evidence of prior attempts. (besides my own bail pitons) I believe the combination of the remoteness and difficulty of the route, the distraction of all the good skiing to be had, and the fact that you have to walk past several other easier and more enticing lines on the way meant that it was neglected until you made it up there.
You didn't rate the climb, but as you know, the route is pretty damn hard, with the angle of the face and the lack of pro being the main problem. If it were more vertical it would actually be less scary. Any fall would be a face-scraping tumbling disaster. One time, the conditions were ideal and there was solid rime ice all along the face, for the right foot and tool, but not enough for a screw. Pro was hard to find.
I would be curious how you would rate it.
Big props to you both for getting it done. Especially climbing up into that overhanging stuff and finding a way. I never got higher than your 2nd pitch. One up there I concluded it was too scary and beyond my abilities, so I abandoned the project.
I doubt your route will see many repeats. Turf Testament was an act of faith.
Congratulations on the FA.