Know what you mean about the use of AE w/ the EL. I had one of those cameras and loved it, except for the "ping" it made when you fired the shutter. Not real loud, but noticeable. My other Nikkormats simply went "snick" w/ that great Copal shutter sound.
You've run into the usual problem w/ old cameras. It's just too much money to have them repaired when, as suggested, you could get a replacement w/ a warranty for much less than a CLA would cost. And even w/ a CLA'd camera, it's an old camera. Something else might, eventually will, go wrong w/ it. If you're attached to your particular camera I'm sure it could be fixed, but not so cheaply. I'd simply buy another one.
Here's a cheap one. Tested, but not fully.
http://www.ebay.com/itm/Estate-Niko...864?pt=LH_DefaultDomain_0&hash=item4ae2b01e80
This one's been tested and works as it should. You couldn't get yours fixed for this price. It's a real beauty too. I have no relationship w/ the seller. If I were looking for a clean and tested EL, this would be it.
http://www.ebay.com/itm/NIKON-NIKKO...569?pt=LH_DefaultDomain_0&hash=item43d538fcc9
My Nikkormat FTn is a GREAT camera, but for AE have an modified FG that can shoot non AI lenses shoot in that mode w/ stop down metering. Nice small package, took 2 minutes to hack it.