It was working great when it was driven into the garage 25 years ago after 95,000 miles of service.

Is it crazy to hope that the carburetor on this '74 Spider will still work ok, without a rebuild, when bolted back on to the (in-progress) rebuilt engine?

I suspect the seals will be long ago dried out, but you may get lucky on that score. Where you will have a problem is if the carb was not completely dry when stored....25 year old gas will have turned to varnish in the needle valves and you may have float problems too. If you are rebuilding the motor, just get a carb kit, it will be worth your time.

Alternatively there is a great deal on a new carb from Mark Allison, mine was toast and I replaced it with Mark's carb and WOW, the car runs like new again!! And that horrible water choke is gone now too....

Good luck with your project!!

yes, you are crazy to believe that carb will work okay. All of the passages will be gummed up and as mentioned, all of the seals will leak