I assumed that each ceiling fan had its own
dedicated switch and wall box. Is this true?

Unfortunately, no. They have one box where the original light switch was.
When the ceiling fans were installed, the original switch was replaced with
one of those double switches that puts two small SPST switches in a single
box.

can you turn off both fan/lites from either of the
two boxes?

Only one box for both fans. Simple on/off control. They currently have to
turn on the wall switch, then use the pull strings to control the fan/light
operations.

I'd like to eliminate the pull strings and install a wall control.

To complicate matters, the kitchen light switch is directly behind the fan
switches. So they both use shallow boxes to fit back to back in the 2x4
wall.

Remove the wall plates and tell us how many wires
(and colors of wires) go to each switch?

They live an hour away from me, and I haven't looked at the fan circuit in
years. But based on the operation, I'm guessing it either has two 14/2
wires, or a single 14/3 wire.

Do you have ready access to the wiring from an attic
space above the switches and fan/lites to allow pulling
of wires if needed?

Yes. Old house, no insulation, easy access from the basement and attic.
Pulling wires isn't a big deal. We're rewiring the whole house anyway. I'd
just like to avoid cutting into the plaster/lath if possible. It always
seems to turn into a bigger project.

Obviously, if I can't find a single control to run both fans, I'll just
install a 2 or 3 gang box and use standard controls.

Anthony