ok, i must be really dense..
i went over to vb.org and downloaded the file from this thread
Steel Blue 3.6.x - vBulletin.org Forum
in it are two xml files
SteelBlue-3.6.1-style.xml
steelblue3.6.2public-style.xml
neither of which appear to be "product files"
usually product files are names "product-xx" and this is confirmed in the documentation
(BTW, i have no idea how i ended up with the evolution style product thingy in there)