Some of these flags have indeed been identified while some have not.
In the list of War Department captured CS flags the flags taken at Blakely and Spanish Fort (just to the south and attacked the same day) a dozen flags are listed as being taken at both sites (Lossing may also have meant both sites when he wrote what he wrote). These were assigned WD capture numbers 445 (actually a US flag of the 5th Corps) through 456.
I have them as follows:
WD 445 - US flag 5th Corps, recaptured by the 97th Illinois
WD 446 - unknown Mobile Depot by the 119th Illinois
WD 447 - unknown Mobile Depot by the 8th Illinois
WD 448 - unknown Missouri unit, Mobile Depot, by the 83rd Ohio
WD 449 - 2nd Alabama (Reserves I believe), Mobile Depot by the 119th Illinois
WD 450 - ANV 4th Bunting from Ector's Brigade, a Texas regiment, Spanish Fort, by the 8th Iowa
WD 451 - unknown Mobile Depot by the 122 Illinois
WD 452 - Unknown Mobile Depot with orange border by the 119th Illinois
WD 453 - unknown Alabama unit
WD 454 - Second National, possibly the 29th NC but may be Mississippi unit instead, Spanish Fort
WD 455 - ANV 4th Bunting, Ector's Brigade, a Texas regiment, Spanish Fort
WD 456 - 39th North Carolina, Mobile Depot, Spanish Fort
I do NOT think that the red SC Palmetto flag was captured at Ft. Blakely as the Citadel group tries to sell us. Its captor, in the 20th Iowa, specifically stated that he got this flag and a large First National as well, in Mobile itself, where his unit spent a few months after the war was over. If he had captured these in battle that is something that he would have clearly recalled and he never made such claims.