I believe the guns taken at the Missouri Depot in Liberty were turned over to Captain Henry Guibor. Bledsoe had a three gun battery: Old Sacramento, a captured Mexican 9-pdr bored out to 12-pdr on a lathe in Lexington, and two guns cast by William Morrison in his foundry in Lexington. Morrison was said to have been a "worker in brass," so perhaps they were a regulation bronze. At the time of Wilson's Creek Bledsoe had one 12-pdr and two 6-pdr guns, so maybe Morrison cast them as 6-pdr guns.

Hope this helps,
V/R,
kip