I've never had the Rumpless Araucana, but she seems good with regard to shape. 
Mahogany shouldn't be too difficult to breed out as it is a dominant gene, therefore if a bird has it, it shows. She appears to have something else disrupting the normally clean salmon breast of a duckwing hen, however again this is likely dominant, as are whatever restrictors the cockerel has. With this in mind, breeding for a clean duckwing is not too difficult with these birds; it's when recessives are in the mix that it becomes complex, as birds can carry those hidden. If you do choose to take them, take a look at the chicks they produce and see if they have e+ wildtype chick down, as they ought; it's the most recessive, so if they have any other e-series in the mix, it'll show in the down.