Dunno about the seatpost in your photo, but if you need a post with more setback, check out the CLB posts sold at www.wallbike.com

Brooks saddles are notorious for not having long enough rails for many modern frames with steep angles. The CLB post provides more setback than just about any other. I was able to use a B-17 saddle on my De Bernardi frame with a 74-degree seat tube angle with a CLB post.