Thanks! Very revealing, that photo of yours. And it makes me think I really do need to open up the motor completely as you've done.
Reckon I'll be biting the bullet later this week....now the precious blower switch has arrived from my ebay seller I'm loath to install it and risk burning it out immediately and repeating the whole sorry saga over again.

btw: the reason I couldn't detach the old switch from its connector [see earlier post] was due to the plastic having melted - excess current I suppose - and bonded the the whole thing together!

I echo your thanks to all concerned for all the help.