Somebody here a while back posted a review on a UV light that had a XP-G-sized footprint. Not sure what it was though, or if there's a convenient source for the emitter.
<edit>Here's the review: https://budgetlightforum.com/t/-/18217
<edit><edit>More info:https://budgetlightforum.com/t/-/20498
<edit><edit><edit>It was YOU djozz! 
Now if we just knew what the emitter was?