I don't know about that mix; I've never used sheep manure, I avoid any peat-containing product on principle (not that promix is bad, I just don't like the way peat holds moisture). Ask rhizome.
Hey... what about reusing your old coco from the canna projects? Flush out... add your manure... ??? Never tried this but hey why not experiment?
And what about hanging strawberries? YUMMMMM you can add them to your sammich