Well, there was a period of time when there was a crossover between ATS-55 and VG-10. The one you're talking about is an Endura 3. I'm not sure how long ATS-55 lasted, but the E3 came out in 1998. It probably had a 4 year run or so before VG-10 became the steel of choice.
I always liked ATS-55. Some guys complained of rusting, but I never had any issues.