I had the same dilemma a few years ago with my father's AE-1. I sent mine to John Titterington and he charges about $50 + shipping for cleaning and calibrating. He is honest and responds to questions promptly.

His address is...

John Titterington
8109 Wenonga Road
Leawood, KS 66206

His email...

Here's what a few people said about him on photo dot net. I wouldn't hesitate in sending him mine.