A few questions about "new" car

Newbie here! This is my first post on the FABO site so please bear with me if some of the questions I ask seem simple. The last Mopar I owned (70 340 Duster) was from 1975 to 1979. Brought home a "new" numbers matching 70 340 Duster last weekend and started cleaning on it today. Pulled seats and carpet and found a few things that I'm am curious about. Were these cars not primed on the inside? The paint on the floorpans is loose in spots and when I lightly scrape it I get shiny steel underneath. No evidence of any primer. Second question concerns the sheet metal flaps along the inner rockers that protect the wiring harness. Are they somehow removeable or are the welded in? There's a bunch of undercoating around them so I can't really tell without scraping it all out. Thanks for any help and I'll probably be asking alot more questions in the near future.

Brian