I know you have the Anniversary 12H-30 75hz and I have to say they sound great in all the clips you have posted of them. I bought a quad of MIE Anniversary 12H-30's and they sounded nothing like my original 1979 1982A cabinet with the original 12H-30 75Hz Blackbacks so I guess I have to chalk it up to lack of consistency on Celestion's part. For me the 55HZ heritage is really good for EVH that doesn't have that wooly quality to it that my blackbacks have at lower volumes that I play at mostly now and my 75HZ heritages sounds great for all around styles and really do sound close to my 1979 original Blackback 12H-30 cab just a tad tighter a newer. Did I get a lucky and get a good sounding batch of Heritages?... it's quite possible. I have posted clips of my Heritage 55HZ of that cabinet only, the 75Hz Heritages are less woody but sound great as well.
I'd love to try Jims take on the Blackbacks but I am fairly satisfied since I finished loading my last two 4x12's with the Heritage 55 and 75hz. If people need a higher wattage type of greenback or 12H-30 I think Jim at Scumback would be the way to go since the Heritages are $200.00 a pop and 30 watt each.
I really do wish the Anniversaries would have been more like the Heritages but to my ears circa 2009-2010 they weren't even close, the anniversaries I had were strident and grating in the highs and quite unpleasant. Was is just that production run that I got that sounded this way?... anything is possible. I bought the Heritages in 2019 so who knows?
If so I am glad I got lucky...