Auto scaling of a model on prorata basis

i have attached an image of a ring.

this ring i have made with 0.40ct of center solitaire

now i want to make this same ring with 1.00 ct of center diamond.

so i want to know do we have any auto command in rhino5 where i can just change the size of center diam and the entire ring gets scaled on prorata basis.

There is no built in tool specifically for this, I guess, no. I’m not entirely sure what the changes you need are, or I would try to make some suggestion…