I used the information you provided to come up with a plan of action for your Lehmann lard-based dough prepared in the Universal Bread Maker (UBM).
First, I used the manteca nutrition facts you posted to determine the weight of one teaspoon of the manteca. That calculation was to see if it is close enough to use the lard entry in the expanded dough calculating tool at http://www.pizzamaking.com/expanded_calculator.html
. For your manteca, I got 0.16461 ounces for a teaspoon. The value used in the dough calculating tool for lard is 0.15285 ounces for a single teaspoon. The two values are close enough in my opinion to use the value for the lard built into the expanded dough calculating tool. As a practical matter, you perhaps won't be able to measure out the differences when using standard measuring spoons.
You indicated that the minimum amount of dough for the UBM is two loaves of bread. You didn't indicate any recommended weight of a loaf of bread, or the amount of dough to make same, so I used the recipe you mentioned for four loaves of bread, using milk, etc., and converted the ingredients in that recipe to weights. Doing this, I got an estimated dough batch weight of around 88 ounces for four loaves of bread. For half of that dough batch weight, which is the minimum batch size for your UBM, we get 44 ounces. That amount of dough would permit you to make two roughly 16" pizzas, with each dough ball weighing about 22 ounces. The actual dough ball weight might be a bit less if there is some dough loss using the UBM. Of course, you can scale the dough ball weight down to around 21 ounces if that is a suitable weight for your purposes, or you can use any other dough ball weight and corresponding pizza size. That is entirely up to you.
So, for your lard-based Lehmann NY style dough, I would use the Dough Weight option of the expanded dough calculating tool with 44 ounces as the target dough ball weight. I would use whatever percent of lard you would like to use for the experiment, along with whatever set of baker's percents you would like to use for the other ingredients (which will give you the flour and water weights). In order to get enough lard in the dough to be noticeable in the final crust and allow you to make a judgment as to its value in a pizza crust, you might consider using 3%, or maybe even a bit more. I will leave that to your discretion.
I described the Sbarro pizza that I made using lard at Reply 56 at http://www.pizzamaking.com/forum/index.php/topic,2061.msg40413.html#msg40413
. In my case, as I noted in the above post, I did not perceive a great benefit from using the lard. However, in my case, I also used barley malt syrup that might have competed with the lard in some way, although I wonder how much flavor a commercial lard as made in the U.S. actually adds to a pizza crust.
I look forward to your results.