Help needed...

A few questions... Can anyone tell me what was used under the fender where it attaches to bay area..? Almost looked and felt like some sort of sealer / glue...and, for those that know and have restored their cars, did you apply what ever it is when redid yours..?
Next, there was a small piece of bare metal? under my fender tag sticking out. I've seen this on other cars too, varying in size...but not on other cars. Why was it put there, and again, would / did you put it back when restoring. I guess it maybe becomes a personal preference thing, as I'm not going for a concourse resto, but I'm torn between, I might as well put it back even though it looks odd with the freshly painted bay...and leave it out because it's not a complete factory, OEM concourse resto. Why was it bare and not painted too...or was it..?
Thanks for the help..!
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