I remember years ago stripping the motor of a 1960 T110, with the one piece crank.
To get to the sludge trap i had to remove the big plug screw, and then insert a pointed nosed pliers to pull out the sludge tube, which was bunged up solid with sludge, hence the big end shell bearings starting to wear rapidly.
As for the tube not being there i don't know. Have you looked in the workshop manual to see an exploded view of the crank, it could be a different set up to the later cranks.
If there ain't supposed to be one there then clean it out real good, and do as henry norton says, change your oil more regularly.