Sadly they were acquired by Amazon and effectively ruined. In theory Amazon sells the same parts but Amazon's search for specialized parts is dreadful, and when you find a part it's often out of stock or available with a long lead time from a dubious supplier.
To me Small Parts is the classic example of how Amazon is systematically stamping out smaller but better suppliers. I'm not sure why Amazon even needed to acquire them. They could have sold those types of parts anyway. I wonder if they simply wanted the smallparts.com url, which now leads to Amazon.
I should clarify why I liked Small Parts vs McMaster Carr: I'm in Canada and Small Parts would ship to Canada, but McMaster Carr would not ship here unless you had a business, but my work was for a hobby.