According to Daniel's "Confederate Cannon Foundries" shows 1535 through 1545 without a notation about bells. The "Edenton Bell" entries are the four before, and "bell metal" the four after.

So my guess is that the Albemarle artillery (battery B) was outfitted with the two 6 pdr 1841's (#1531 & 1534 and two 12 pdr howitzers #1532 & 1533.) This assumes that this was a four gun battery at formation and it agrees with the Battery B info you have listed for Dec. 1864.

I'm a bit surprised they were still using 6 pdr guns and 12 pdr howitzers in late 1864. This suggests that perhaps they were keen on hanging onto the particular bell metal they had been charged with using/protecting. (Just a guess.) The material on hand would have only been sufficient to recast two full Napoleons with about a half gun remainder (especially considering the bore and excess that would be required in casting.) With the battery stationed out of the main field armies there would have been less justification for re-equipping them as well.