Considering the last one was built around 50 years or so ago, what percentage of each is original? Is the such a thing as an original b-52?
Just wondering.

It's about time! I've always said the problem with the B-52 was its limited payload. The standard B-52 loadout only includes eight AGM-84 Harpoon missiles, four AGM-142 Raptor missiles, fifty-one 500-pound bombs, thirty 1,000-pound bombs, twenty AGM-86C conventional air-launched cruise missiles (CALCM), twelve joint stand-off weapons (JSOW), twelve joint direct-attack munitions (JDAM), and sixteen wind-corrected munitions dispensers (WCMD). That's only 153 total.
I remember reading about a pilot who flew the same B-52 his grandfather flew.
The AF is also looking at another engine upgrade.
There was a conversation some time ago to re-equip the B52s with 747/777/787 type High bypass engines, replacing the 2 engine pods with a single HB engine. This was dropped in the argument that the 8 engine config.gave greater combat redundancy.
Why? The range, climb benefits, less spare parts and greater reliability.
My choice would be the Pratt Geared Turbofan, the PW1133G/GA-JM, PW1130G-JM 33110 Pounds of thrust takeoff, 32780, continuous, per Wiki.
A bit less than their 34,000 lbs combined for the two old TF-33's, I am sure they can push it.
Looks at the TSFC, 0.78 lb/(lbf·h) for the TF-33, vs. an estimate of .35 ( CFM 56 - 15%, ) Pratt is claiming 15% lower TSFC than it's rivals, and I can find a published number for a TSFC pf .2975 estimated vs .78. Yeeeowzer...


Despite the Air Force always wanting cutting edge bombers, the vast majority of its work is done by these antiques.
So the simple matter is why not build a “more modern” version of the B-52 workhorses? More than anything else, the production should be focused on a small number of things.
1) Better materials. The science and technology of materials has exploded since the 1950s, so that we can make them more durable, lighter, stronger, etc., with little extra cost.
2) Redundancy. One of the biggest advantages of the A-10 Thunderbolt II (”Warthog”) is its redundant systems. Many of these aircraft were just torn apart in combat, yet their pilots could still land them.
3) Low maintenance. It is essential for these aircraft, as they are now so they need to remain.
4) Better engines. This technology has changed a lot. But fuel efficiency and power must be balanced against maintenance and durability.
5) The complete redesign of its weapons bay to maximize it for many different weapons.