HI - no one responded to my question, so I guessed noone had tried the base stuff. So I put my own concrete base down. I took pictures of how I did it if anyone wants to know how. Cost £100 all in. Attached is a picture of my shed all finished. All 50 stone of it.
Took an hour to get the batons level, 30 mins to pour the concrete, 2 days to set. Then 4 hours to build the shed.
This is my its my garden shed