727 long tailshaft speedo drive

imhaving trouble finding a speedo housing for my 727, its not the normal large housing like my short tailshaft 727, the hole in the tailshaft is much much smaller. i cant find anything anywhere about this!
can someone please point me in the right direction?

The small hole is '65 and earlier, there is no removable speedo adapter like the '66 and later, the bottom end of the speedo cable plugs directly into the tailhousing.

thankyou so very much!