Is it compensated for the unwound G string? The early wraptails were designed for the thicker, wound G strings typical of early '60s string sets and apparently this is where the intonation issues come in. I'm hoping that my 2006 reissue has a bridge that is not an exact replica of that early bridge
What was the Badass bridge like? I've been contemplating getting one of the repros from Stew Mac if I have an intonation problem
As you mentioned, the original bridges were made for a wound G string (and most cheap copies of those bridges are still made that way, bizarrely). But in recent years, Gibson have been using a slightly redesigned bridge compensated for an unwound G, which works fine (at least to my unsophisticated ears). That's what was fitted to the Pete Townshend SG I had a few years ago.
The bridge I've just bought has the unwound G compensation, I got it from a German seller on eBay. I'm pretty sure it's an actual Gibson part, but aged for a relic effect. They have them in both chrome and nickel.
I personally don't like the Badass bridge, it works fine (and has some vintage appeal, I suppose) but I think it's ugly and I don't like the feel of it under the hand. I much prefer Pigtail or TonePros. The Schroeder and Graph Tech ResoMax bridges (also available from StewMac) look good too, but I haven't tried them.
(No idea what to do about your yellowed pickguard, I'm afraid)