Despite my best endeavours when rebuilding the engine, i landed up with the situation that the rotor arm was 180 degrees out i.e. if i have pot 1 HT lead the opposite side to where it should go on the distributor (and do the same to the other 3 leads), the engine runs fine. In the ideal world, i would remove/refit the distributor drive deep in the engine, but that is not going to happen given where i am at.
I can leave things as they are - the engine runs fine. However, it would be nice to get the leads looking better.
Is it possible to remove the top parts of the distributor and get the rotor arm facing 180 degrees the other way?

Take the distributor out completely and turn it 180 (the rotor arm). Just be careful when you put it back don't loose the driving dog into the engine. A bit of grease will help it stay in place as you get it lined up

I thought the end of the distributor had an offset tooth, which won't fit into the drive dog.

This is what i see in the book...

As per previous photo post..
Pull out dizzy & rotate. Number 14 will turn.
Number 23 does not need removing.

Bottom of dozy is a square shape and will drop in