MkIV TT wheels sit too deep into the chassis on the front, the 17x9.5 +50 rim will likely rub on the lower control arm. I have a wear spot on such control arm from it doing exactly that. You'll likely rub some tire on something with a 275 rubber set on the rim. I would think +40 or +35 offset would be more ideal if you didn't want to chop stuff up in the wheel well.
I'm not saying you can't run them, they're just not an ideal solution, especially since people seem to think $800 is a fair price for a full set... meaning you'll spend a buttload to get old cast rims. You could spend the same and get better fitment in a custom rim. The backspacing on the 9.5" rim is perfect for the inside rear, but horrible for the outside rear, the rim is quite sunken into the wheel well. I would get a 17x10 or 17x10.5 with the same backspacing and pull the fenders.