I am sure that you are aware of these reports and descriptions of the guns in question, But I quote them to counter Lt Thompson description.

"...and my artillery--six mountain howitzers and three small steel-rifled guns..."

Col. Powell Clayton commanding at Pine Bluff from his report 10/27/63 on the action at Pine Bluff 10/25/63.
(O.R. ser 1, Vol 22, part 1, page 723)

"...I ordered the light battery of English steel rifle cannon..."

Lt Col THOMAS N. PACE, commanding 1st Ind Cav. (O.R. ser 1, Vol 22, part 1, page 726)

Certain I would guess that the Brigade and Regimental commanders would certain know what kind of guns they had assigned to their commands.

Lt. Melvin C Wright commanding the 3rd Iowa battery in his report no 11, dated July 5, 1863, on his part in the Battle of Helena stated that his Battery was supported by the Battery from the 1st Indiana Cavalry and again refered to as "...a battery of steel guns..."

All three of these men describe these guns as "Steel".

a material that the Blakely guns were made of, while I believe that the Parrot Gun was a cast iron gun.

Lt. Colonel Pace identifies these guns as "English".

Certain the Parrot gun's origins were well known and familuar within the armouries of the United States Army and would not have been described as "English". I can not imagine why anybody above the rank of 2nd Lieutenant would have misidentified a parrot gun as being of "English" manufacture. It was very well known by both armies.

These are just two descriptions that stand in contrast to Thompson's statement. And all things considered it would be a Colonel, and a Lt Colonel's word, against that of a Lieutenant's, from another regiments.

As for my interest in the Mtn Howitzers of the 5th Kansas. We know there were 6 at the Battle of Pine Bluff. However, Col Clayton reported one of these guns captured by Confederates during the Battle of Mark's Mill 4/25/1864. However, the Confederates reported Capturing two of these guns. A third Mtn Howitzer was supposedly dumped/abandoned in the Saline River at Mt Elba crossing to prevent it capture.

So I was interested in how many Mtn Howitzer (3, 4, or 5)were at Pine Bluff in January 1865. Or if maybe they had been returned to Little Rock along with the 1st Indiana Guns by that time.

As for when these 12# Mtn Howitzers joined the 5th Kansas A report by Colonel Lewis Merrill commanding 1st Brigade, 1st Cavalry Division, dated September 16th, 1863, Ser.1, vol 22, part1, page 496, listing in the table of organization that these guns belongs to Strange's 2nd Missouri and Lovejoy's Merrill horse Batteries.

"Artillery.-Captain G. Stange, Second Missouri Artillery, commanding; six 12-pounder mountain howitzers of Stange's Second Missouri and Lovejoy's Merrill Horse Batteries; two 6-pounder rifled steel guns, prairie carriages, attached to the First Indiana; Clarkson's battery, Second Missouri Artillery, two 3-inch rifle and two 12-pounder (heavy) howitzers"

Notice again the 1st Indiana's guns are described as "Steel" and "6 pounders" "(on) Prairie carriages". certainly not a carriage strong enough to support a full scale Parrot gun.

Appearently they became permanately attached to the 5th Kansas Cavalry when they were sent to support Col Clayton just prior to the Battle of Pine Bluff, 10/25/63.