I had the opportunity to see this Golgo 13 limited edition Tuna Can last Saturday. This piece belongs to a fellow collector who purchased it directly from Japan. From what I understand, he purchased it from one of the sellers on Japanese site, Rakuten.
This watch is very much the same as the SBBN017 except for the black coating and red accents. I also noted that the shroud has glossy surface instead of brushed or matte surfaces like the SBBN015 and 017.
Here are some cellphone shots of the watch.