MERCEDES BENZ W113 THROTTLE BODY BOSCH A1131410125 - eBay (item 150457848631 end time Jan-15-11 10:41:00 PST)

Not an endorsement for the seller; and although I did buy one of those I haven't received it yet (due to the power of holiday UPS, not the fault of the seller) so I can't testify to the quality.

This is the correct item, though, if the part number is right (which I believe it is), and the price is quite competitive with what TVT were charging.

From my understanding TVT's 74mm throttle bodies were just this item recycled from similar eBay sellers / chop shops and polished up.