I'm drawn the most to the Amar, Mayfair and Walden filters. I would like to know which real cameras they are based on, or inspired by, if any?
In general, they're not based on any camera. Kevin Systrom, the co-founder and ex-CEO of Instagram, said the following in How does Instagram choose names for their filters? on Quora:
I wish that I could say it's more interesting - but often it has to do with the inspiration for the filter... a type of film, a photo we've seen, or simply what we were doing at the time.
For the video filters, AllThingsD has the details, but there's no one theme.
Here's a blog post that tries to reverse engineer the filters into camera/film combinations: http://blog.1000memories.com/97-old-school-instagram-filters-using-vintage-cameras-and-film
Unfortunately, it doesn't have Amaro or Mayfair listed. And for what it's worth, my personal experience with a Yashica Mat-124G with Velvia 100 didn't come out looking the way they said it would: