As an unashamed Harry Hazlewood and Hazlewoodcatalogueophile it is distressing that most of my photocopies of the catalogues are of the rose lists only. They are missing the first few pages where Harry Hazlewood explained things.
1922 was the first of the detailed catalogues with first-hand, warts-and-all descriptions rather than copies of the breeders/introducers' descriptions. On page 1 of the 1930 Hazlewood Bros.catalogue 'Favourite Roses and Other Plants', Harry Hazlewood writes this about the Hazlewood Bros. catalogues:
"In 1922 a new departure in catalogue standards in Australia was inaugurated by our firm, when descriptions giving the main faults, as well as the qualities, were first published. This step was considered very necessary as quite a number of rose which are considered worth while in England or the Continent developed serious faults in many parts of Australia. It was felt that to publish verbatim the original description was altogether misleading and not ethical.
It was realised also that every client was entitled to any expert knowledge the firm could supply which would help to prevent loss of time, inconvenience and disappointment caused by planting unsuitable varieties. As far as practicable these ideas have been put into operation and results achieved testify most emphatically that the average Rose purchaser greatly appreciates being taken into the growers' confidence.
Every sensible individual accepts the position that the perfect rose or plant is not yet available. As tastes differ enormously, any service rendered in aiding the planter to avoid disappointment by planting sorts free from what they consider objectionable factors must inevitably tend to raise the standard of Garden Craft.
Two years later (1924) a further innovation was introduced by which Australia was divided into Climatic Zones, in each of which the roses definitely known to be successful were noted. This method has been before the public for years and it is felt that while not yet perfect, the idea is quite sound and has a very solid scientific basis. A great deal of investigation has been put into this question of suitability to climate and it is confidently asserted, that where followed out intelligently, this method will prevent much disappointment and failure.
Where there is any difficulty in knowing what to plant, in a given district, full recommendation will be cheerfully supplied on receipt of all particulars.
Clients desiring assistance in this direction, are asked to state class of soil, rainfall, elevation, local factors governing growth such as degrees of frosts, etc., and in addition should state their preference for colours, types of blooms and any other features desired. If a list of varieties already growing is supplied recommendation will be made as to how the collection may be improved.
To summarise, the dominating feature in this catalogue is to ensure as far as possible, the success of our clients by helping them to avoid unsuitable sorts, by advising as to the best methods of treatment, and by supplying stock as free from defects as it is possible to produce.
ORDER OF PREFERENCE - Throughout 1929 a careful tally was kept of all varieties sold, and we have listed them in the order of preference, decided by buyers from all the States. In explanation we wish to point out that each plant ordered this season is counted as a vote for that variety to determine its place in next year's catalogue. This method may not find general approval as an alphabetical list makes it easier to find a given sort. In the new method, however, it brings all the very best varieties into a prominent position, and selection, particularly for a beginner, is made much easier. Frequently we have handled orders made out for commencing a rose garden, and a list numbering 50 odd plants had been selected, which did not get beyond the first four letters of the alphabet. Success under these conditions is most remote. ...The index simplifies the finding of any one sort, so that the objection to our method is outweighed by its advantages."
HH writes further under the headings 'Stock for 1930', 'Varieties' and 'Descriptions' including some useful notes about the description of scent.
The thoughtful comments at the bottom of each page contain many gems and are a joy to read.

I hope your appeal here turns up Hazlewood Bros. catalogues from the 1911-1921 period Patricia.