Hi,

It's true that MoT test standards will vary from station to station. This isn't always because one station is 'right' and the other is 'wrong'. One tester's 'pass & advise' could be another's 'fail' How bad a corroded brake pipe needs to be, to justify a fail, can depend on how many burst ones you've actually seen.
Personal experience and product knowledge play a large part. No mechanic can know everythng about every make and model. In the past 34 years I've tested in excess of 25,000 cars and seen standards change quite a lot since the 1970s.
Some items that were once a certain fail in the eyes of VOSA (It was the Ministry of Transport when I started, then Dept.of Environment, then Dept.of Transport.....) are not even considered testable items now.