where should I tie into harness for column to console conversion and other wiring

That's a welded splice.
If you need to splice you can solder but I also like the open barrel crimps. 67Dart273 has posted a link to a Chrysler ref on using them for splicing.
For the terminals, I assume you have 'open barrel' terminals and crimpers. If not, also do a search here for 'Chrysler terminals'

To answer your question about converting to console - use the factory wiring diagram and the pdfs that we've linked to in other posts.

For what you want to do, the Faxon book with the assembly drawings is also very helpful.
Its not the best quality reproductions and has annoying watermark but its still worth the $35.
The drawings show where the console cable connects to the main instrument cable, etc. etc
68 is different than 67.