My initial question had lots of answers, and my second had too many constraints. So, I have removed some constraints and added another. Same rules as before, but we are now using $[0,6]\cap\mathbb{Z}$. Also, the four corners should sum to $15$, the number at top-left.
15 5 --- --- --- --- 15 7 11 --- --- --- --- 11 17 8 10 8 --- --- --- --- 13 13 15 --- --- --- --- 7
Can you solve this diamond grid?