Such estimates are difficult to come by because the conditions of generating empirical evidence do not often occur or, at least, are not often recorded. Entrepreneurs make such estimates in making business decisions, but the public data recorded is usually just the wage rate and the number employed.
Richard Vedder is a fellow-traveler of Austrian economics who has ventured to make estimates of MRP in the case of slave labor. Here is one Vedder article on teh topic:
http://www.jstor.org/stable/3741279
