At first glance the Blue Dress looks like a typical bustle dress. But when you start to take it feature by feature, you begin to realise that there is no dress existing that combines all the features used, at least none that we can easily find.....
The neckline of the original dress was really very low, and scooped with false revers (with a curved neckline these "revers" would have been impossible to simply fold back.) So the change to a high v neckline in the Australian version does bring what is suppoed to be a day dress more into day dress style.
The use of an apron and a bustle drape is fairly common in the 1870s and 1880s, but not combined with panniers.
The bow on the back of the dress is also a fairly uncommon feature, and can be rather hard to find.
The use of stripes and the use of blues, and the use of blue prints is extremely easy to find. Blue floral stripes however are a different matter, though some have shown up in extant items on ebay recently
The waterfall drapery is also unusual in the size and creation of the drapery.

There are also aspects of the shaping of the dress that could come from the first and the second bustle periods, as well as the natural form era the musical is set in.
Maria Bjornson made great use of the book "Victorian Fashions and Costumes from Harper's Bazaar 1867-1898" and used two plates directly, with very minor changes. There is a whole page devoted to what features the dress shares with historical dress on the Inspirations page.
The Australian wardrobe deviated most from the original designs when compared to the other productions. This goes further than use of trimmings. Here follows a breakdown of the dress from bottom up, from structural to superficial changes.

Skirt Construction:
The original skirt was gored and shaped with a small train. This is how all the other productions have made their skirts as well, the actual gore shapes differ slightly though, and some skirts have a trim around the hem. Some skirts are supported all the way to the hem which some have much less support and shaping. The Australian versions (and World Tour/South African productions which used them) actually had fully pleated skirts. The pleats were all box pleated, however the arrangement of the pleats differ from dress to dress. The World Tour dresses use a double box pleat. All pleats are made so the scrolling floral pattern in the silk is on the face of the pleat.

Drapery:
In the original design, the apron drape was cut in two parts on the bias to create a chevron effect and trimmed with a pleated ruffle, the pannier drapery was only bordered with trim and the waterfall drape was edged with the same trim as the bodice and apron drapery. The waterfall drapery was lined in shot taffeta. The bow at the bottom of the bodice is tailless, wide and puffy.
In the Australian dresses the apron drape is created on the straight of the fabric so the lines go vertically. The panniers were trimmed with the same pleated ruffle as the apron drape and headed with a heavy braid trimm and fringe. The waterfall drapes were a three fold (so that you see the face and the lining three times each.) The waterfall drapery was only trimmed with a border of velvet ribbon set in from the edge.
The pleats on the apron and the panniers were finely knife pleated and trimmed with a medium and narrow line of velvet ribbon. The waterfall drapery was lined in shot taffeta. The dresses used by the World Tour show the same velvet ribbon used on the inside as well.
In many respects the drapery is reminiscent of the Canadian dresses. The bow at the back of the bodice is long, flat and relatively narrow, bordered on each edge with velvet ribbon.

Bodice:
The bodice like the skirt deviates in construction as well as ornamentation.
The bodice originally was cut to the hip bone in the front and slightly longer in back to fit over a small bustle (either bustle pad or layers of support inside the dress) and cut using modern princess seams. The neckline was a low wide scoop with fake revers of velvet trimmed in a wide scrolling floral pattern from the same tufted braid used on the cuffs, drapery and down the fronts of the faux vest front. The tufted braid was also used to create a scrolling pattern on the upper velvet cuffs and the faux vest. The faux vest butted edge to edge at the front and "closed" with blue covered (?) buttons. The sleeves terminated just above the elbow and were cut on the straight of the fabric. The upper cuffs were trumpet shaped that narrowed towards the inside of the elbow. The lower cuffs were made from the same silk as the body, shaped to dip lower in the back and knife pleated. There was a ruffle of gathered lace that just peeked below the lower cuffs. A matching ruffle at the neck is quite obvious.
The Australian dresses were very much longer, just as one sees in several photographs and fashion plates of the late 1870s to c1881, and cut from modern princes seams. It also fitted quite loosely over the lower hips and bustle pad (or other internal support.) The neckline is much narrower and a very acute V shape with actual turn down revers. The revers were decorated with embroidered realistic flowers and leaves. The same pattern is seen only at the top and bottom of the faux vest, and not on the cuffs. The faux vest overlapped edges at the front and "closed" with blue covered buttons with a gold border. The sleeves terminated just below the elbow. The upper cuffs were made of velevt bordered with the same silk as the body of the gown, they were a more flared trumpet shape and narrowed towards the back of the elbow where there was a flat bow of velvet ribbon. The lower cuffs were pleated much more finely, shaped to dip slightly in the back and trimmed with two rows of narrow velvet. There was a ruffle of gathered lace that peeked just below the lower cuff. The matchign ruffle at the neck is not so obvious. The World Tour now has a very obvious ruffle again.