Prima Luna Prologue 3 rolled some tubes and...

My 2 channel system is pretty modest. The room upstairs is small and shaped entirely wrong. My budget is limited. I swap stuff regularly. A lot of it. When I coupled my Job 225 with a Prima Luna Prologue 3 something exciting happened. It was audio nirvana, a gorgeous balance of the Jobs lightning fast attack and high end sparkle coupled to the PL's laid back tube sound. My current speakers are LSA 1 Statements. The PL had new matched Gold Lions in it. As fate would have it, I bought a hand full of Amperex Bugle Boy 12ax7, 12au7 and some Telefunken 12ax7 tubes, along with some old equipment from an estate. I paid $200 for all of the equipment and the tubes. So my wee little brain thought, tube rolling? It might just work. Sure enough the tubes tested well and after about 5 minutes of warm up my jaw hit the floor. My oh my, what a change! After a day of swapping things around I settled on a pair of 12au7 Bugle Boys, a pair of 12ax7 Telefunkens and the Gold Lion GZ34s. The soundstage gained height, width and depth. The instruments and vocals had more air, but were also more focused in relationship to each other. Highs are clean and warm. Bass is solid and tight, but a tiny bit lean in the lower frequencies. My wife walked in and she asked what I had done to system.  In my mind, if I had spent $1k to get this much improvement it would have been a bargain.  So here are my questions...

1. How/why do tubes made in the 1950's (Amperex dated 1949 & 1950) sound better than my modern Gold Lions?

2. Is there a better combination out there?

3. Since swapped tubes make a huge difference what would happen if I swapped out capacitors, resistors etc?