You need the entire set. You don't get +25 health, scouts always have 125.
Unless you have a Sandman, which knocks off 10. But gives you a baseball.
Of course, I could give you the full set if you wanted +25 health. But then you'd be using a Shortstop and Mad Milk, which would totally change the way you play. I personally think the set makes you play scout the wrong way, but you can always borrow the things for a while.
The Shortstop is a bastardization of the Scattergun and Pistol, giving the scout a higher damage output over longer distance. Mad Milk is tossed on enemies and people hitting said enemies get health back for hitting them. In all, the set is good for becoming a support or tank-ier scout, but it removes the flank-and-wreck strategy.
