Hey dude, i had similar issues finding blocks for non standard sized cards,
Your best bet would be to go with something like a heatkiller, they are compatible with a wide variety of cards and even if yours isnt listed as compatible it may line up.
I also looked at Barrow and Bykski theyre japanese brands that make blocks for all kinds of non standard cards.
With my Zotac gtx 1060 mini i went with a bykski block that had a matching bolt pattern.
Sorry if this wasnty a great help just thought it might benafit you to know what options are available.
Been in tech support for 6 years, Ive been designing and building systems ever since!
OCN for the win!