OP, I did some homework and I found out what might be the closest equivalent to the
High Gloss Muralo Ultra around right now. I looked up Graham Paints and found they made a high gloss ceramic paint, and I remember reading back in the day Graham and Muralo were basically relabels of each other. The Graham Paint is no longer around, but apparently it's been relabeled "Fixall High Gloss Enamel" according to other paint stores on Google.
This durable 100% acrylic, ceramic reinforced waterborne enamel provides a durable High Gloss finish for many general maintenance requirements. It provides superior color retention and moisture resistance when used exterior and is rust inhibiting when applied in the proper system. *Note F52104...
www.fixallpaint.com
I swear the gloss level of the Muralo version of this is exactly on par with gloss white oil Rustoleum, if not higher gloss, and it leveled even better than oil based Rusto did in a side by side test I did. It's absolutely amazing paint. So California is apparently still making it under that name (you can see the ICP Construction on the bottom of the page.)
That was done with a microfiber roller, not sprayed, and came out like that with the Muralo version of that paint. So hopefully California kept the "Fixall" version as good, but it was disappointing to see no high gloss in a normal Cali line.
DEFINITELY carry that paint, though, OP.