Help identify modular shelves. To refinish or not?

I picked up this awesome (to me) modular shelving unit the other day for a great price. It's a bit rough and I can't tell if the painted areas are original or not. It looks like they may be. Since it is so rough I would like to refinish it but don't want to go down that path if everything is original. Any thoughts on when it was made and by who? I'm thinking it is mid-century, late 60's maybe? Any help would be most appreciated.

https://imgur.com/a/Wwrfxx2