Question: Can I get shims to level bessa blocks?

I am erecting a 5M x 2.4M POD in our backyard.

The welded tubular steel base looks like this and will be supported on nine pads.

Each pad is a half bessa block (0811049) sitting on one or more pavers (3451556) depending ground slope.
I need shims for the 190 x 190mm blocks.
Cheers