Hi, the Jobling catalogue just shows the bowls as 'table bowls', that is to say without any fittings. Sadly I don't know if Joblng sold these as lighting bowls themselves or just supplied them to others to be adapted.
Personally I think all of these bowls are very good quality, though the earlier Lambton Rose and Bird designs are my favourites. Some say the modelling of the mermaids bowl is arguably not as good as on earlier pieces as it's in lower relief and the dolphins, for example, aren't that naturalistically modelled. Jobling's Iris lighting bowl is an almost exact copy of a Verlys design. That said, all are very desirable and the mermaid bowl is seemingly very hard to find and something I'd love to own.
The Lambton Rose bowl was available in green, blue, amber, pink, clear satinised (like your example) and opalique. I don't know what colours the mermaid bowl was offered in, but would imagine that it would be a similar range, though again I'm not aware if opalique was offered post-war. Certainly I've seen the design in pink and possibly in green. There's at least one pink example in the Jobling display at the Sunderland museum.
I'd certainly be interested in seeing more details of the mermaid bowl as that's a pattern I don't own nor have good pictures of. Also pics of the fittings might be of interest as someone might recognise the maker. You can email them to me if they are too big to attach here.
There's some further reading on these bowls here: http://www.glassmessages.com/index.php/topic,49888.0.html