mono cartridge vs stereo

If our modern day audio press were interested in education, a la the dear departed Audio Magazine, they would run an article explaining "mono" cartridges and the technical differences between vintage mono and modern mono recordings. But they're in business to sell stuff, whether buying makes sense or not.

I suspect there is no difference between using a modern mono cartridge that is really an internally bridged stereo cartridge with modern mono LPs vs a mono switch on your preamp with those same recordings. With vintage mono the groove width is different and the idel stylus shape is different, and to get that optimal geometry you have to have a mono cartridge built to do the job. At least that's the state of my understanding.

I think just about everything you need to know is in this thread, except which carts are true mono. That, and tip size are what make a hugh difference with vintage mono recordings. If you have such records in your collection and play them with a real mono cart, you'll hear the difference immediately. The entire presentation changes for the better.

Strapping the channels on a stereo cart is slightly different than using a mono switch. It might not matter, but you're cutting the cart impedance and inductance in half on most carts. That might depend on the physical orientation of the inductors (coils). A mono switch in a preamp usually comes after the phono EQ circuit.
Maybe having the phono stage channels hooked together halves the input impedance as well?

I checked out the specs of the Ortofon 2M Mono carts. They seem to be strapped 2M stereo carts just like it says in the mono overview. They're designed to play modern reissues methinks, and the SE model's shibata stylus would seem to confirm that.
2M Mono - 350mH, 700 ohm
2M Blue - 700mH, 1.3K ohm
2M Mono SE - 300mH, 600 ohm
2M Black - 630mH, 1.2K ohm

I think the hard part might be figuring out if your reissues are cut with a stereo or mono cutter.

Guys, I have a single tonearm available to me, and it is set up for stereo. I've got two questions:

1) When using the Y adaptor, do you need two Y adaptors, one to sum the L+R channels and one to redistribute them back to L+R outputs?

2) If you definitely don't have a mono cartridge, is it better to buy stereo re-issues of mono LP's?

Oh, and two other things. I'm assuming that with the Y adaptor approach, you're not just taking one channel and splitting it into two. That you are in fact blending the two channels and then distributing the blended signal to two RCA's.

I should also add that I have an outboard phono preamp. I assume that I should place the double Y adaptor device between my phono preamp and my linestage preamp?

There is no VS if you have many mono records you get a mono cartridge as well.