Just get the TNN's..
I've ground my rim once near 2 month ago, usually first grinds don't hold to well and go blunt quickly. My grind has blunt a wee bit but my pads are still performing like they were the day I ground my rim. No tar or anything just a fresh grind is all that's needed. I haven't had a better brake.
Cheers. That drop gap is Damon material, it doesn't look that big on those photos, but when you're on top of the wall it's just a no no.
Cheers Cocky, get yourself up here soon.