Throttle Shaft Leak

I tuned my SU's and the engine sounds pretty good but couldn't get the rear one as lean as I wanted. I took the car to a Swedish car mechanic with SU experience and he said I'd done ok but the throttle shaft was leaking air. Then he quoted an estimate that tells me he planned to take several hours to seal the leaks. Haynes shows 2 throttle spindle seals, a cold start seal, a spindle seal, and an o-ring...are replacing those the job? It looks like a pain, with lots of tiny parts! Is there a way to tell if the throttle shaft is really leaking?

by no way am i am expert i really dont even know what you are talking about a throttle shaft leaking air but couldnt you cork up both ends and put a basket ball needle in one of the ends(throught the middle of the cork) and pump it up with a hand or foot pump(like for bikes) and see if the pressure holds. i have tested other things like this but never a throttle shaft...oh yeah you can get rubber or cork ends at home depot...another thing you could do is pressurize it the same way and rub soapy water on it and see if it bubbles(would show air leaking) or you could just find a trustworthy mechanic like one of the ones on the bbs

I presume that any throttle shaft leak would be a vacuum leak and if so there's a super easy way to check it. With the engine idling at operating temperature just spray some WD40 or other flamable spray around the throttle shaft. If the engine changes speed, usually an increase, the shaft is leaking.

Spray carburator cleaner on the throttel shaft.

Not sure if it will work on your carb, but I've fixed other carbs, distributors, etc. that were worn with good old J-B Weld. Coat the shaft lightly with mold release or similar, then mix up some J-B Weld and build it up around the opening where the shaft goes through the aluminum. When hard, you can then remove the shaft again, smooth the epoxy with a file or sandpaper so it looks better, and it should last a LONG time. Maybe I'm just a cheapskate, but when parts are unavailable or very expensive, you does what you gotta do.

No need to go to the lengths vern described.
Throttle shaft leaks can be repaired fairly easily depending on where the wear is and how bad it is.
The first step for me is to remove the throttle plate and slide the shaft out until a 'unused' portion of the shaft is in the body. Then wiggle to see if there's any play. If there's no appreciable play, the buy a new standard size shaft and replace it and you're done.
If you're not so luck, and there's still quite a bit of play you can go the second route, and order a .010 oversized shaft, have the body reamed to the oversize with a piloted reamer, re-build and you're done.
In the worst case, you can have the body bushed with bronze bushings, reamed to standard size and put in standard size throttle shafts, problem solved.
As you can tell, variing degrees of expense involved, depending on the level of the damage, but if you're going to fix it, fix it right.
H.