I just went through this just a couple months ago, I wanted the "real" 1613 that everyone loves for the early Mustang Black Semi Flat Black. Turns out you can still get it, just not through any big box hardware store. I called up Krylon direct and found out not only did they change the SKU number even though it's still 1613, but they actually transferred me to another department which was not for retail. It's now called Industrial Krylon 1613. I can probably pull the info off the unopened box I just purchased if people are interested. But basically I called them up made sure we were talking about the correct formulation of the popular 1613, and then they told me several places I could go get it. Turns out one was only about a mile away from where my car was at the time in Fremont so I was able to just walk in and buy it. They have plenty of places that either stock it or that you can order directly from and have it shipped.
The place I got it from was called:
Fastenal - 37420 Cedar Blvd, Newark, CA 94560 - 510-796-4521
Hope this helps,