When you think that the Minor was introduced right back in 1948 and was a pretty inexpensive car, I think the design (and execution) was quite remarkable. My own Minor 1000 is a comparative youngster at a little over 60years old but is still perfectly capable of reliable daily use.
I really don't think replacing the master cylinder is THAT bad a job - and anyway, how often do you have to do it!
If you have ever driven any other car from the 1940s you'll soon realise how far ahead of any of the competition the Minor was
As Mr Pike says, it isn't always a good idea to fit the bolts the "wrong" way round. I've never heard of them wearing through the torsion bar but I know that they can create a rattle when they come into contact with it