Ok, so a further update on things now that I've reseated the intake boot. The whistling noise still exists, although it is fainter than before. I have to strain to hear it even under ideal circumstances.

I'm going to call up the stealership today and order new seals (and wastegate hose) and we'll see how things change (if at all) after I install those.

__________________
1984 300D Turbo, 326000 Km, Thistle Green Metallic