Thats really neat. The black was replaced with red and whats usually red is pink. I think you can clean this up and make it presentable without damaging or changing the authenticity of it. I would leave the drops that are missing the star as that does stand out as different. When you say "bleached zeros" are you speaking of the dummy score reel label? If so I don't think your hurting the value installing repro. New flippers and pops doesn't hurt anything either unless they are a completely different mech. Which I highly doubt they are.

I restored a regular production run Big Deal recently so if you need photos check out this thread: https://pinside.com/pinball/forum/topic/1977-williams-big-deal-barn-find-

As for value I think condition is still king. But you may run into someone who is wanting the odd ball example and is willing to pay a bit more. I wouldn't sell my Big Deal for less then $1200 and thats with a blown out backglass.