Vac Pump Failing? Front Rattle OM617

[isobars]

Hello Everyone,
I’m sorry to make my first post a cry for help, but I’m in need of some advice - I hope that I can make some useful contributions in the future!
I’ve a recently acquired OM617 Turbo with a rattle towards the front of the engine bay.
Could anyone identify what’s causing it from the Youtube recording, please? Sorry it runs a bit long!
OM617 Turbo - YouTube

There’s also a leak in the fuel primer – see the last few moments of the video. What problems will this cause – it does seem a little sluggish but flies when the turbo kicks-in.
The second vid is my low mileage om617 na, just for a comparison.
OM617 131,500kms n/a - YouTube

I’ve had suggestions that it may be the vacuum pump – I can’t even find it! Is there an easy test for this, or does it simply have to be listened to closely or touched to feel the rattle?
If the pump was failing, would there be other symptoms?

Update:
I've just had another good crawl around underneath, the propshaft continues to turn (auto-box) because the plastic selector bushings are shot, it might be the noise is from there?
Thanks in advance.
Cheers,
Paul