Welcome Swallow? Fairy Martin? Please help with ID's

Hi everyone

I'd like some help with these photos, all taken in Victoria Point, Qld.

The first I am fairly sure is a Welcome Swallow, colour, markings, sitting posture all match with my book,

" Fleurieu Birds" by Peter Gower (South Australian photographer)  I picked this book up while in Goolwa SA at Christmas time. It covers local and migratory birds on the peninsula south of Adelaide, and right across the Coorong National Park.

The second photo I'm not so sure about - I believe these are Fairy Martins. We have had these particular birds build nests which are the distinctive bottle shape mud nests Peter mentions in the book. The birds seem to sit differently on the wire than the first bird.

My confusion is caused by the variations in colours between the three birds in the second picture.

Or do we have all three birds, Welcome Swallows, Fairy Martins and Tree Martins?

Any assistance appreciated

Thanks

Chris