HLB values are pretty easy to calculate. Swiftcraftymonkey's blog has tons of great HLB information on it, and I figured out how to calculate it from there.
OR, even easier, you can find an oil with the same/close HLB value (wheat germ oil is 7), and with the same general oil properties/oil weight and sub it into your recipe. Other oils with a HLB of 7:sweet almond, sunflower, soybean, sesame,rice bran, olive, macadamia nut, grapeseed, evening primrose, canola, borage, apricot kernel, and avocado oils. And more. BUT not all of those will work- look up the properties of the oil you are subbing for, and see if the properties of any of these oils match up. sweet almond or apricot kernel oil would probably be a good substitute.