You might try contacting Intermatic directly:http://www.intermatic.com/customer%20service.aspx
As a serviceman myself, I can tell you that selling parts for stuff ends up with serviceman spending time on the phone helping to repair the thing for free. Not just that, but servicemen have to salvage parts and know which parts to salvage, and then inventory the parts, and remember where all that dang stuff is ... and with overhead, and cost of labor and trucks, the part costs the same as a service call. So hire the guy or buy a new one.
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Also take advantage of fixya phone service.
For a price, expert speaks with you over phone while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.