Here’s a link to photo of one of the Austrian “24 pounder” field howitzers displayed at Gettysburg. Of course the carriage is generic and incorrect for the tube but may be similar to what the Confederates used. I see similarities to the model’s tube in the dolphins and integral sight base. As far as I can tell the models tube and carriage have always been together, but since I wasn’t always with the item, there is of course some room for doubt, but I’m 95% certain tube and carriage were made to be together, whatever their nationality. I have a contact at the military museum in Vienna, maybe he’ll know something.

https://en.m.wikipedia.org/wiki/Field_artillery_in_the_American_Civil_War#/media/File%3ACW_Arty_24_Pound_Field_Gun_rear.jpg