Austrian Artillery - Liechtenstein System

I was looking at this diagram that I copied from Christopher Duffy's book, "The Army of Marie Therese" and I'm trying to determine if the Liechtenstein System of artillery used during the SYW used a standardized wheel diameter for the 3-pound, 6-pound, 12-pounde and 7-pound howitzer  artillery carriages.

In Stephen Summerfield's book, "Austrian Seven Years War Cavalry and Artillery" states that:

Precise standard for carriages, limber, cart and wagon wheels were introduced. Feuerstein was concerned about increasing the operational mobility of the ordnance so two wheel sizes for all artillery transport was used. (Does "transport" mean the artillery wheels as well as the wagons?").

Looking at the diagram above, it looks as if all wheels for the gun carriages are the same size. I am hoping tat someone can confirm or refute this contention or assumption.. Your help will be much appreciated.

UPDATE

I looked a little closer at the Duffy book and he states that:

Liechtenstein established a common axle and just two types of wheel for the whole range of field artillery and supporting vehicles. He thereby ensured that spares were always at hand in the event of a break down. The 36-inch diameter wheel served as the front wheels of the large ammunition cart, and the 51-inch wheel for the field guns and howitzers, for the small two wheel ammunition cart and the rear wheels of the large four-wheeled ammunition cart.