You've probably seen all those "Frost" ballasts I got over the months.
Here's an eBay listing for a newer "ATC-Frost" FBAK-10-05 preheat ballast.
Here's a picture of the label:
This model is technically identical to this Frost FBAK-12 I own:
The ballasts listed on eBay have "06.12.04", which I guess is the date code (Dec. 6, 2004), pretty recent but preheat chokes are really reliable, and the listing says there are 64 of these available! Kind of expensive though...