I hope that this partial answer to the above queries is of use. I confess that up to now my research (and painting) had been concentrated on the minor German states and the French opponents, and I have only recently started on Dutch and British forces!

First, regarding the colour of Austrian gun carriages, the earliest specific mention of the yellow colour associated with them later is in the Artillerie Systeme ab Anno 1753 (Artillery System of 1753) in the Austrian Kriegs Arkhiv, which I quote:

"The gun carriages and the wheels are to be painted all over ... the wood in dark yellow, and the ironwork in black. This practice... gives much better protection than before (my emphasis) against damp and other climatic conditions..."

This implies, at least to me, that the artillery material was not protected by painting prior to 1753. I have not been able to find any contemporary (1700-1715) illustrations of Austrian or Imperial artillery to confirm or deny this. However, other German states' artillery equipment in the War of the Spanish Succession was frequently unpainted, at least the woodwork. Specifically, artillery equipment of Pfalz (Palatinate),Wurzburg, Wurttemburg/Swabian Circle, and Hesse-Kassel is described as "natur oder holzfarbern" natural, or wood coloured.

Concerning battalion or regimental guns with the Imperial forces, the following is what I have gathered on the subject from various German sources:

1. Franconian Circle: no mention of battalion artillery, either among the regular infantry or the "supernumerary regiments" raised in 1703.

2. Upper Rhine Circle: Only unit with battalion guns was the Hesse-Darmstadt Regiment, of 10 companies in 2 battalions, which had 2 3-lber guns in 1703. Carriage colour is not specified.

3. Rhine Bishoprics (Mainz-Trier-Pfalz): Only artillery appears to have been fortress guns at Trier, and possibly Mainz.

4. Swabian Circle. In 1702 had 5 infantry regiments with 15 3-lber iron guns cast in the Wurttemburg Eisenwerke. In May, 1702, Swabian units in the Lines of Stollhofen had 25 3lber and 25 6-lber guns, all locally made iron pieces. In 1708 Swabian infantry totalled 4 regiments with the Imperial forces, with 12 regimental guns. Carriage colours, where described, are unpainted wood, with "blackened" iron.

5. Salzburg and the Bavarian Circle: no battalion guns mentioned.

6. Wurzburg: In 1702, had 4 regimental guns total, for the 2 infantry regiments of Fuchs and von Bibra. No other battalion artillery is mentioned for any Wurzburg units. I believe these were 3-lber guns, as there is a 3-lber piece (unmounted) on display in the Marksburg Fortress Museum in Wurzburg dated to "early eighteenth century". That one gun, at least, is bronze.

7. Upper Saxon Duchies: No battalion guns mentioned from any of Saxe-Weimar, Saxe-Gotha, Reis-Schwarzburg, or Anhalt-Beyreuth.

Not specifically Imperial, but part of most Imperial armies, were forces from Palatinate (modern Rhineland-Pfalz), and the "hired" troops of Prussia and Denmark:

1. Palatinate: Had 2 battalion guns for each infantry regiment, with black ironwork and unpainted woodwork. Wagons (presumably including ammunition carts) were painted in red or blue and white stripes, with the Colonel ("Inhaber's") or the Elector Palatine's arms.

2. Denmark: No battalion guns are mentioned in the contracts for troops with either

the "Sea Powers" (Holland and England) or the Imperial forces, and the detailed organization given for the initial infantry units supplied to the Imperial forces do not list any artillerymen of any kind.

3. Prussia: Had 1 gun for each battalion, either iron or bronze 3-lbers are mentioned, but I cannot verify this from a contemporary source, and feel it may be from later, after the middle of the 18th century. A tapestry from the 1680's already shows Prussian guns with dark blue carriages and dark, presumably blackened, iron fittings.