New starter
The extensions are covered by the plastic cover (red circle). Look closely at it, you will see how it pops off. Unbolt the extensions at the actual starter terminals (yellow arrows, under plastic cover) and attach your cables there, if they reach.
As far as a clockable starter goes, it would be much cheaper to just put longer cables on it. Which may not be the worst idea anyways, rather than trying to keep using 50+ year old cables.
The extensions are covered by the plastic cover (red circle). Look closely at it, you will see how it pops off. Unbolt the extensions at the actual starter terminals (yellow arrows, under plastic cover) and attach your cables there, if they reach.
As far as a clockable starter goes, it would be much cheaper to just put longer cables on it. Which may not be the worst idea anyways, rather than trying to keep using 50+ year old cables.