I'm sorry but i think you are missing the point. I am not arguing about the specific numbers you put into your model, but the entire premise.

You are mixing highly subjective values with quantifiable values into a mathematical formula and are expecting a meaningful output. This does not make any sense. The VSL is it self very subjective. It is a tool designed to estimate what we are willing to pay to save a life. Mixing in the EQ and slaughter age is nonsensical and does not yield any sort of meaningful number.

As for the cruelty calculation this is nonsense as well. The original number from the study sounds like it was based on what people where actually paying in dollars in order to reduce cruelty. I don't know how it was calculated so i can't comment on that. However, it is clearly different from what you are doing, by multiplying brainsize with age. This doesn't yield any sort of meaningful result. your might as well multiply the height by the eye color. What is it that you expect that number will tell you?

If you wan't to create a tool for people to use based on VSL, just have people estimate how they value a human life in relation with a cow life. I.e. how many cows should you save in order to justify the loss of a human life. This is essentially what your doing with EQ/slaughter age calculation. This way people can evaluate for them selves what the "morality" cost is for them.
E.g. someone who doesn't value a cows life at all will get zero dollars in "value of life" and someone who values it at 1/50 like you mention will get a similar number to you. This approach is not flawless, but it is every bit as accurate as yours, actually makes a bit of sense and might actually be useful for people to calculate their own moral in dollars like what seems to be your aim.