I'd weigh the cost of restoration over the cost of buying a new, or great quality used, kit. I'd also consider my intent - is it to play or just flip? The first consideration, either way, is cost. How much must I invest to render it playable? If I bought, say, a 4 piece tangerine sparkle set of Gretsch shells for $400.00 and I'm going to keep and use it, then I'll render it playable and tunable. That may require edgework, new heads, some hardware replacement, and maybe a rewrap or refinish job. That all might set me back maybe $800.00, in which case I've paid $1200.00 for a tangerine G sparkle kit, not a bad price from what I've seen. Depending on the sizes, I could likely flip that for at least $1500 and maybe more. If I'm buying just to flip, then I'll do as little work as possible.