BlackCurrent, that isn't a name I've heard in awhile! I used to work in the food manufacturing industry 10 years ago. We where one of the few companies involved in manufacturing black current oil - at that time. Not much black current oil was made when I was in the industry, but it seemed to have a loyal following.
I haven't taken black current oil to see if it helps with my IBD. I have taken flax oil though which is high in ALA, along with primrose oil which has GLA. The combo made my skin appear nice, but didn't seem to help my condition.
If I can ask, why are you avoiding fish oil? If a vegan, and concerned about an animal product, I believe there is an algae created DHA sold in some health stores. Fish do not create EPA/DHA from what I understand. They obtain their omega 3s from dinning on algae or plankton.