New starter

Professor Fate said
View attachment 1715836708
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.

I don't think they'll reach there, but thanks for the detailed info. Battery cable is new. The black ignition wire would be no problem replacing with new, as it's a single wire coming from the relay. It looks like the best I could do with the red battery wire would be to cut it after it comes off the relay and do new wire from there to the stud.