Check condition of rear brake pipes that go up and over fuel tank - a common MOT fail - most places will charge you £200 up to replace as they drop the tank ( although you don't have to ).
If brakes feel warped it can be the bushes at the rear of the front wishbones or the balljoints on the same wishbones - check carefully before doing discs/pads .
If it feels flat and idles erratically it's probably a new cam sensor. Get a diagnostics done for about £30 - surprising amount of old BMs have got a sensor down