Hi.
Some drums are easier to ID as a rewrap than others. 60's-era Ludwigs are easy to identify due to the fact that the original wraps were tucked into the scarf joint and so the original wrap leaves a remnant inside that scarf joint. You can see it easily when you know what to look for.
Some rewraps are better than others, too. A more modern technique of rewrapping is to use double-side tape instead of apply contact cement to the entire surface of the new wrap. It's a time-saver and less toxic...but the tape method often leaves air-spaces and voids and can actually detract from the resonance of a drum.
As far as the silver sparkle on the hoops of a black wrapped drum....I'm not sure if it was common to Slingerland or not (my guess would be "Yes"), but I KNOW that was the scheme that Ludwig used to use. I play a custom-built Magstar kit built by Rob Kampa in that exact scheme -silver sparkle on the black-painted bass drum hoop and a black wrap on the shells -this was based upon a vintage Ludwig prototype. The idea of doing that (in my opinion) was to kind of match the look of the chrome rims on the other drums.
Many new wraps jsut don't look like the old ones. Certain white marine pearls are less rich than the vintage ones, for example. The more drums you look at, the easier it will become to ID just what they are. You can look up finish-options in the old catalogs and see what the real wraps look like and then compare those with what modern suppliers have available.
I know that there are different black wraps, too. The new black wraps look glossier and a little less classic than an old black wrap -such as the old Black Cortex wrap, for example. So, when you get familiar with these things from basically just looking at a lot of them, you can tell a rewrap from ten feet away! ;)
