Like Steen said, the D12's never caught your ear because they are essentially half a good kick sound. That is why they are paired with other mics to capture the attack. All of the original ones are going on 50 years old and will be in various states of repair. It will not be a good workhorse kick mic for you.
The D112 is more midrangey than most newer kick mics. It does capture the sub low end, but you have to shape the midrange to bring it out. The cool thing about it is that you can put the attack of the kick anywhere you want it. 1k, for that late 1970's sound, 3-4k for that late 80's sound, or high shelf at 8k for that more modern heavy metal kick sound. With some other mics, they have already sucked out some midrange and added the highs and lows, so you will need to EQ around that in order to make the kick sound different.
You're overthinking this. You can get the kick sound you want from just about any kick mic. There is no need to get too fancy.
Also, don't fall for the idea that the only legitimate 421's are the vintage ones. No, the new ones don't sound exactly the same. But the old ones don't sound like they did anymore either. And it isn't 1972 anymore, time, tech and audience expectations have changed. A lot of people love old led zeppelin albums, but if you came out with an album that had the exact same sonics as their first album, people would think it sounded like crap and was too quiet.
Hell, the drums on Master of Puppets were miced with nothing but SM57's. It didn't affect sales or popularity. Don't overthink this, or get stuck in the mentality that you need a specific version of anything.
Also, don't rule out the Audix kick mic, it is pretty good too.
I agree. I'm definitely overthinking this whole thing. I just made an offer on an original e602. It's the first one I've seen for sale in the three weeks I've been looking for one. Hopefully I'll dig it.