Wow
Hi Richard, well you can safely say it sounds like no other Hoover heard before!!, the only time I ever heard that was on a machine that the heater mounting bracket had come undone and the heater was rattling!!! (not for long before it shorted) given what you found in the pump and the noise I hasten to think what it might be, cant find a pic of an inside to check, but the repairers here will confirm if that metal could be a mounting bracket!!
Theres definately something rattling!!, have you checked wires & hoses nr the motor / pump / pulley?? to make sure nothing is catching!!
For a vintage machine that does appear to be a full load, used like that every day will wear it out quickly, I would advise lowering the load so you have a good drop and flop motion!!
Good luck, Mike