Good design is good design, is good design. The 'tube' sound is so many things from so many different tubes that it is as definable as the female form... yeah, they've all got tits [+/- 3db]... but that's pretty much where the similarities end.
Both of the items you've mentioned, the A-Designs and the Pendulum are excellent sounding units... they sound quite different, and according to your sense of aesthetic, one may be better than the other for your applications... but frankly I'll be damned if I could say which one on an internet forum... especially having never met you nor heard your music.
That "60's upfront sound" is a combination of many, many, many factors. First... you had for the most part, great microphones. The PRC didn't realize that the music business existed at that time... and Banjo Mart was a single store on Sunset Blvd. in Hell-A... things like the A-Design and Pendulum type products were the norm rather than the exception.
Except... that the only "stand alone" mic pre's were like the RCA stuff which was built and distributed for broadcast applications... in other words, what we have now is still different from what was available then... no matter how you modify your dead dad's original drawings, nor model number you put on the face plate... he's still dead, and the product isn't sitting in the rest of the infastructure that helped achieve it's somewhat signature tone.
The point of this is that you're going to get a myriad of opinions here... some will be worth looking at for your application, some will not. How can you tell the wheat from the chaff? Hell if I know... perhaps you kinda sit back and watch how the people debating this subject debate... watch how they post on other thread to determine if you're of similar or disimilar tastes [as much as one can make that determination on an internet forum], then move on from there.
Personally, I think damn near any well designed pre-amp, from a GML to a D.W. Fearn to 20-30 points in between will probably satisfy your requirements... but that one "perfect" pre, like that one "special" woman will always be a personal decision that you will have to experience to understand.
With that said, let's also remember that a chain is only as strong as the weakest link... which means that microphone selection and placement, A/D-D/A conversion, as well as the mix and balance of the sounds that comprise the final presentation will be as important as any other element in the recording process... and that the performance capabilities of those recorded will be of far more importance than any of the recording tools.... but you do have to start somewhere... so you might as well start with a good pre.
Best of luck with the search.