Sad reflection of the UK pinball scene, There is however a huge collector interest in these machines, I had three myself until recently, all my sons young mates used to come round & spend hours playing.
You can get most of the spare parts easily but some flipper solenoids are hard to come by for 1980's era machines. Pinball clubs hold open weekends in various places, you pay a small admission fee & find 100 or more machines all on free play, all will be in proper working order. You can buy 1980's era's for £100 if you have room to put it, cheap ones called 'player' machines will be in working order but in poorer condition, pristine ones called 'collector' machines sell for big money for rare machines.
Look on Ebay to see stuff available