From the Mermaid walk down the steps towards the bay and take a path rising up the other side. I think that it passes behind some small huts rather than actually going across the bay itself. Anyway, up the other side there is a fairly obvious overhanging face to your right, just over a small depression next to the path. The right hand side of this is 'ope in hell' (the second of your photos) which is apparently 7b+ and well worth doing.
If you continue walking away from the bay you'll come across a quarried wall (not the one visible from the ope in hell boulder!) which i think is where the other two problems in those photos are, but i've never tried them so can't comment. There looks to be a fair amount of rock around that stretch of coast.
I emailed Ben off the Dorset climbing website for a bit more info after doing ope in hell to confirm i'd done the right problem (i met a guy at the cuttings who told me that he'd heard rumours of this mythical problem!) and he reckoned there was quite a lot of stuff there that was never documented, so might be worth contacting him if you want to know more. Or pm me and i'll try and help.
