Well, you have done very good research, as a good translator should. The problem with squashes is that there is such a huge genetic variety across a great many species that a one-to-one "translation" might not be the best.
I do a lot of cooking myself (& I love vegetables), & a lot of US magazines (Bon Appétit, Food & Wine, etc.) will qualify their suggested ingredients with what the original recipe called for & what people in their country-of-distribution-of-the-magazine might be able to find locally.
Whether that's true & the same in German, that's up to you as the translator.
And, again. I love them all on my dinner plate. In as many different ways as I & my wife can fix them!!! Fresh, & home grown.