Yes, we made this for 70+ people and at the moment our memories are such that it is easier to say how we did it for that size, but obviously this recipe can be cut down to something a bit more manageable.  In fact the ingredients are all mixed by taste and feel anyhow, so use your own taste and imagination, it will be great!

2 128 oz tins of tomato sauce
256 oz of water (ie fill the tins)
12 to 24 oz. tomato paste
8 large onions, diced
2 large heads of garlic, separated, peel and minced (more or less to taste)
olive oil
140 bell peppers (1/2 green, 1/4 red, 1/4 yellow)
15 lbs good quality Italian Sausage
2 TB dried oregano
2 TB dried basil
salt
pepper
sugar
hot sauce

Remove the sausage from the casing and, in a large pot (ok we ended up using 2 HUGE restaurant pots for our 70 people recipe),  saute in some olive oil, breaking it up into small pieces. Remove from the pot, drain on paper towels, if desired and refrigerate. In the same pot, saute the onions and garlic until soft and a little golden, but do not brown. Don't burn the garlic.  Add the tomato sauce, the water and 12 oz tomato paste. Add the basil and oregano. Add salt and pepper to taste. Add some hot sauce (ok we just like to toss in a lot Tobasco in everything) to taste. Bring to a boil then simmer...

Meanwhile, roast 1/2 the peppers, remove the skins, seeds and stem and slice.

After a few hours or so of simmering, add the peppers and the reserved sausage (crumbled) to the red sauce. You can correct the flavors using more tomato paste, salt and pepper.  Also if it doesn't taste "red ripe" enough you can add some sugar.  Brown sugar often is nice for this. We used both brown and white sugar.  Add the roasted peppers and the reserve sausage and simmer.  Our overall simmer time was something like 8 hours for all this sauce.

At this point we froze the sauce, to be reheated just before serving.

Roast the rest of the peppers, remove the skins, seeds and peel and slice.

Serve the sauce over the peppers and include plenty of bread to sop it all up.  Also provide best quality reggiano parmesan to go with.

Note: we basically aimed at one pepper per person in the sauce and one pepper per person for the sauce to go over.