Nikon 80-200mm f2.8 Repair

Hello,

I have an old Nikon AF-D 80-200 f2.8 push pull zoom that has an aperture that does not close fast enough in the auto indexing to expose properly. I've been told
It's possible due to oil on the blades. Where might I send this to get repaired cheaply in the Philadelphia area? Thank you for any input

KEH repairs in Atlanta does great repair work. I sent them my 80-200 for work once. Fast and reasonable.