Full authenticity would also require raised flooring, and an audio track of people shouting "SAVE YOUR FILES!" whenever the lights flickered.
Bad news if that was the monitor of course.
A consequence of that was that anything that took a memory address could access the registers as memory. Just give it an address in [0,15].
That included the program counter. Load code in 0-15 and jump to it and it would run quite a bit faster than if it were in core if your KA-10 had the fast register option.