I would grab that new one on Ebay, even if you happen to get your present one repaired- - - -that's a steal at the asking price, and it looks like they might accept a somewhat lower offer. A 40-year-old NOS part is worth having, especially one that's as scarce as that one!

I'm doing some macro digital pictures of the service manual pages- - - -they should reproduce better than scans.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!