Apparently not many people on these forums know much about the Sega CDX
In any case, in general many of these older regulators won't be switchmode and as such won't be regulated as you might be used to with modern adaptors. With that in mind its important to measure the voltage and current draw while the system is on. From you only showing the voltage of your power supply (at an elevated level) I assume you were just measuring the power supply while it was open circuit and not powering anything.
TLDR: measure power supplies when they have their load connected. Your '14.5V' supply is probably 9.5V under load.
As for the model 2 adaptor, the same thing will be happening.
As far as running the 11.5V system on the 12V the short answer is: not likely. What it will do is cause a slightly increased temperature inside the case (and I mean an extra 10% of waste power being produced) and strain your PSU components a bit more but probably not worth enough to worry about.
Thanks for the reply!! I tested the voltage under load and it reads 12.06v. Measuring the voltage not under load it reads 12.08v. So the voltage drop is minimal under load, when seeking in Sega CD mode. I don't know if an OEM adapter would stabilize at 9.5v under load. I do notice the bottom of the CDX gets a little warm after a half hour of use, but I think that is normal with all consoles. I think I might get a modern linear voltage regulator that is more robust to be sure this CDX won't burn up on me. I might even add a metal plate to the LVR to act as a heatsink to dissipate excess heat as well. Thanks again for your input, it is greatly appreciated!
I will let everyone know how it goes.