A Blakely identification for the First Indiana's guns is only the most plausible. I've a strong tho entirely circumstantial case, but have not found an explicit identification.

Though there are rumors of other recoveries elsewhere, the documented "Britten" 2.9-inch projectiles from the hills above Helena ("exactly" where the First Indiana was aiming on 4 July, 1863) are likely from these guns. "Britten" projectiles are English, like Blakely guns. F.Y.I.: 1862 and later manufactured Blakely's have "ratchet" rifling grooves, but any made in 1861 would have straight grooves.

My only reservation about all "2-inch" and or "2-pounder" guns in Missouri (& close by) being Woodruffs, is that there are other --essentially local-- possible makers of such small caliber guns. Mr. Woodruff has merely gotten all the press. There's a great (Missouri Artillery) web site which features one of these other types, but I can't remember the details.