At Cara's (Los Altos, CA, back in the 50's) we took pork shoulder, boned it, and ground it by hand.
Next we used a large platter and formed the ground meat into a flat 'loaf' about 3-4" high.
Then we spread salt on top of the 'loaf' until the surface was white.
We spread pepper on top of the salt until the surface was brown.
Finally we spread fennel on top of the salt and pepper until the surface was pebbled.
At that point we plunged our hands into the loaf and mixed in the spices.
(I can still remember how cold that felt.)
We did this about once a month, and froze most of the sausage in used (10L?) olive oil tins.
The beauty of this process is that it worked regardless of how much pork shoulder we had ground.
And it was quick.
In those years, red pepper flakes were not that common in Italian sausage or on pizzas -- at least not in California.