That might be a different model carburetor which uses a bushing that slides in the carburetor body and accepts the threaded needle valve. The bushing has the needed internal threads and is held in place by the compression of the packing washers as the needle retaining nut is snugged down.
Might not fit your 1952 though.
You can see the bushing #34 on this parts diagram:
https://www.boats.net/catalog/evinrude/outboard-by-hp/18hp/18802a-1968/carburetor-group
