Did I miss something Again?
Where has it been said money has been paid? Looks to have come from the same place that insisted that another member was threatening to shoot some body.

Since you know that the block has a 13mm hole. This tells me you have since pulled the blocks out or Mr Muffler informed you that they wont fit because this hole is too small.
Is the locating pin on the leafspring wider than 13mm or is the hole in the block not deep enough for the locating pin? Either way you should be able to drill it to suit.
How is the fit of the pin ontop of the block when its mated to the diff?

What makes a competant tradesman? Is it a repairers license? Because you dont need to be a tradesman to get a repairers license.
Is a competant tradesman someone who has completed a trades course and apprenticeship and has become certified?
To me an incompetant tradesman is someone who begins an apprenticeship, then fails to complete it but still feels they can pose as a Certified Tradesman.

There are many parts that get fitted to cars that are illegal and can be defected. But show me on any pinkslip or blueslip where these can all be failed during a rego inspection.