You can often get messed around by dodgy eBay sellers who delay knowing EBay will kick the problem if it’s not within their stated time frame for returns etc.
Decorating ,stood on a stool to reach the ceiling but forgot about the low shelf , compressed spine , paralysed below neck for a few minutes , few days in hospital before I could walk properly .
If you are changing the bath take a hole saw to bath just below tap which will allow you to replace it .
Patch with a plastic patch siliconed on till you can replace bath .
Clamps for hobs usually extend 20-30mm beyond the cut out.The diagram seems to show spring clips for the side and optional clamps where the the worktop may be unsuitable for spring clips (for example 20 mm work top )