BattleTech: Gray Death Legion (1986)

From the back of the book:

The Gray Death Legion scenario set describes major battles fought by the unit, as told in the novels Decision at Thunder Rift, Mercenary's Star, and The Price of Glory. You will follow the Legion's rise from a mere three 'Mechs to a full combined arms regiment feared and admired by both enemies and friends. The set also provides the statistics and condition of the Gray Death Companions and the conditions of their 'Mechs. Also included are 15 scenarios of some of the more notable battles fought by the Legion.