All the regular sources for those dried up. Templar Precision has some parts, but that regulator might not be one of them. The only option left after that is to hope someone puts one of theirs up for sale in a forum or an auction site.
Do you have a Delorane? And a hangout with a quirky old scientist? And you’ll need to help him build a flux capacitor with a output of 5.5 jigs watts of power.
After that my friend it should be prrrreeetttyy easy to get one.