Regarding calcium: Boyd Eaton has published work suggesting that
paleolithic humans average quite a bit more calcium intake than most modern
Americans take in.  But they get it all from meat and green vegetables and
nuts, all of which they eat in abundance.

There is significant evidence that the phytic acids in grains--especially
unrefined "whole grains" contributes to depletion of minerals, especially
calcium.  I had a nutritionist suggest to me long ago that humans can't
readily digest the calcium in greens and that we can only get it from
dairy, but that sounds like bullshit to me; my suspicion is that it's the
phytic acid (and possibly the glutens and other things) in the modern diet
that makes it so hard for us to withdraw the calcium we need.

Regarding fibre: again, according to researcher Boyd Eaton, paleolithic
humans on average probably ate a hell of a lot of fibre--more even than is
now recommended.  I believe his recommendation was for 150 (!!) grams of
fibre every day.  But of course if you're following a hunter/gatherer diet
almost none of that will be cereal fibre; you'd get it from sources like
nuts and fruits and berries and green veggies.  OTOH, the Inuit eat just
about zero fibre on their all-meat diets, which is damn close to what you
eat, Grant, so I don't know just how worried I'd be since they seem healthy
enough (they die of the infections and injuries our modern doctors can fix
with ease, not from colon cancer!).

As for a typical paleolithic human diet: the best practical description
I've seen is in Ray Audette's NEANDER THIN.  But a basic rundown looks like
this:

Meat (any variety, but include organ meats if you can--fish is also
included here).
Eggs
Nuts (any variety of true nut is fine, just skip things like peanuts which
aren't really nuts, and stick to almonds, walnuts, etc.)
Berries
Fruits
Any vegetable you can eat raw

Simple breakfast: fried eggs, grapefruit, almonds
Simple lunch: two pork chops, some blueberries, a nice salad with olive oil
and lemon juice (try to skip vinegar)
Dinner: steak, broccoli, a nice salad, strawberries

Snacks: hard boiled eggs, apple, banana, pear, nuts, dried fruits, etc.

Beverage: water preferred.  Fruit juices okay but probably not good to
overindulge.

You can do a lot with that.  There are neat recipes you can do if you get
tired of the basic variations, but you wanted simple.