The original Jeff Rose ignition was an Electromotive HPV-1.
(Current Electroair is also made by Electromotive... shush shush!)

(It's an XDI.)
I had spoke to Jeff a number of times and he never did say it was an off the shelf auto unit. He adapted it and created a manual for airplanes.
I have been running the old JR and have replaced a JR unit with the electroair HPV-1. (Cuz it's identical.) I have also found that the HPX (Purple body) from Electromotive also will replace the HPV-1. They do use a different vacuum sensor however. I found several used ones on Ebay.
Here's the manual.
https://electromotive.com/wp-content...15/05/hpv1.pdf