Well I didn’t claim Greenpeace etc. were transparent. I was talking about non-specific lobby groups and think tanks in that paragraph.
However, I would say that funding my lots of small individual donations counts as transparent because influence of any individual donor is minimised (though it would be nice to see numbers of donors of big amounts).
I’m not a donor to any of the groups I mentioned, but (quick look at accounts on web) 90% of FoE’s 2 million funding is from individuals. 95% of Greenpeace’s rather larger funding is from individuals at 77 euros each (so they have 2.5 million donors).