OK,
So it sounds like it mainly a timing issue, when they jump a cam belt tooth they sound like an absolute bag of nails! but that is not to say the cam timing is out as most don't seem to reset the cam position when changing the cam belt and in my experience it makes quite a difference to how quiet the engine runs!
It sounds like it may have skipped a pump timing belt tooth when it has been smoke tested it or what ever they test when revving the F*** out of the engine for while moting it!
Ideally you would be best to change both belts but you may want to start by changing the pump timing belt first just so you can be sure that is the issue....
There is some info here on changing the belts etc
https://www.justanswer.com/uk-car/3r...-injector.html the main bit to remember is the cam shaft isnt keyed so you can move the sprocket on the cam if the adjuster pulley isn't giving you enough adjustment.