what's the difference between 974 and 974 special?

this is the picture.thanks for all the help.

One difference is the 974 has a brass escape wheel and the 974 special has a metal escape wheel. Other than that I'm not sure.

Check out this thread!


https://ihc185.infopop.cc/eve/f...173982477#2173982477

Jun welcome to the site. I see you joined in August.

thanks，Eugene Buffard。