I've just been consulting my wee hillclimbs book and it lists a couple of climbs in the area we were in yesterday which may be of interest.
One, in fact which we descended. The road down to Garvald past the iron age fort with the smell of heather in the air. This is described as "White Castle" and the climb up from Garvald to the fort is 4K or 2.65miles with avg gradient of 5.8%.
The other climb is Bransly Hill which is the next road to the east of White Castle - looks like it can be accessed via Stenton then Spott. The book describes it from south of Dunbar as 6.85K or 4.3 miles at 4.8%. The road from Spott joins it before the steep section, so you wouldn't be missing the "good bit" by going that way!
Finally, if we had turned right at the top of Redstone Rigg and descended toward Duns - these are the descents of Mainslaughter and Hardens. The climb from Duns up to Hardens Hill is used as the setting for a local hillclimb competition. The climb up from outside Duns to Mainslaughter is 9miles at an average of 3.2%. The "steep" bit comes at Longformacus - no chevron - so can't be that steep. So it must be about 12 to the top of Redstone Rigg. Must be some descent! I hit 47.5mph yesterday on the descent from the Rigg. (Tug was going faster!).
Just noticed this thread. Think I passed you guys at the junction after the descent off the Rigg and the road to Garvald. Sounds like you had a great day.
It's definitely worth checking out the other climbs mentioned here, I really like the White Castle climb, I find myself climbing into the Lammermuirs this way more often than not. I suspect subconsciously I'm trying to avoid the steep bit of the Rigg.
There is nothing particularly steep about the Mainslaughter and Hardens climb, but it's very, very long. Done it a couple of times and I've found it tough.
Not sure if this is the Bransly Hill climb but the way into the Lammermuirs from Spott is cracking, slightly trickier navigation though. Had no idea the road existed before doing it in an audax.
http://www.strava.com/activities/66999848