[Arran]

I believe that all of the under chassis mounted filter caps are aftermarket replacements, the originals would have been mounted where those two empty clamps are on the front right hand corner of the chassis. Those two stud mounted ones are some sort of foreign style dry electrolytic, it's possible that they may be original for the British market, depending on how many this set had to begin with. More then likely the stud mounted caps were just put in by some long departed repairman since they took advantage of the factory ventilation holes to install them.
Regards
Arran