Old Rayleigh and Shanks are carbon copies of each other, both in fighting style, also design wise and carefree attitude. I say Old Rayleigh because he was introduced first, and that's exactly who he is. They are used interchangeably in the story for Oda. Both are representations of walking haoshoku haki (both were used for introducing CoC in the story despite dozens of other characters having it, Shanks making GB twerk was immediately followed up by Ray making BB twerk).
If you didn't know this scene you wouldn't be able to tell if the above gif was Ray or Shanks, that's how similar they are.
Rayleigh was not modelled after Zoro's template, not one bit. They share the 2nd strongest rank in their respective crews and some other similarities (drinking and scar) but you can find those similarities in dozens of other characters (including Shanks). The only thing Zoro and Ray share is the fact that Zoro will probably surpass him in power at some point.