Brake lights not working and MOT in a week

Hi all.
My rear brake lights are not working and I'm running out of things to check/replace. I've researched the forum and from this ive done the following:

Check the fuses (They were fine but I've replaced them anyway)
Checked the bulbs (again, fine but replaced anyway)
Cleaned contacts between bulbs and lighting backplate
Checked wiring (seems OK)
Replaced both brake switches on the master cylinder and replaced the old rusty connectors with new spade connectors

I've noticed that the fuse for the brake lights (number 7 in the board) is 8A, and the spade connectors I used were only 5A, does this matter?

Any help would be great, I'm really struggling as I think I've checked everything.

BTW it's an '82 cabrio with a Series 1 15 bullet fuse board.

have you got a multimeter?  I would get an assistant to press the pedal while i first check the voltage at the master cylinder switches, then if thats ok, check the voltage on the terminal going into the light cluster, then at the connector for the bulb.

by working through from the start of the circuit to the end you atleast know where the voltage is getting to, and therefore where the problem lies.